diff --git a/frontend/src/components/SearchableValueSelect.tsx b/frontend/src/components/SearchableValueSelect.tsx
new file mode 100644
index 0000000..95df7cc
--- /dev/null
+++ b/frontend/src/components/SearchableValueSelect.tsx
@@ -0,0 +1,153 @@
+import { useEffect, useId, useRef, useState } from 'react'
+import { useTranslation } from 'react-i18next'
+import { Input } from '@/components/ui/input'
+import { cn } from '@/lib/utils'
+
+interface SearchableValueSelectProps {
+  /** Visible label above the field; omit or set hideLabel for toolbar chips. */
+  label?: string
+  hideLabel?: boolean
+  ariaLabel?: string
+  values: string[]
+  value: string
+  onChange: (value: string) => void
+  placeholder?: string
+  /** Show a leading empty option (e.g. all namespaces). */
+  allowEmpty?: boolean
+  /** Label for the empty option and closed-state display when value is empty. */
+  emptyLabel?: string
+  loading?: boolean
+  disabled?: boolean
+  className?: string
+  triggerClassName?: string
+}
+
+/** Searchable single-value combobox for long option lists (namespaces, labels, …). */
+export function SearchableValueSelect({
+  label,
+  hideLabel = false,
+  ariaLabel,
+  values,
+  value,
+  onChange,
+  placeholder,
+  allowEmpty = false,
+  emptyLabel,
+  loading = false,
+  disabled = false,
+  className,
+  triggerClassName,
+}: SearchableValueSelectProps) {
+  const { t } = useTranslation('logs')
+  const [open, setOpen] = useState(false)
+  const [filter, setFilter] = useState('')
+  const [active, setActive] = useState(0)
+  const root = useRef<HTMLDivElement>(null)
+  const id = useId()
+  const emptyText = emptyLabel ?? t('select.any')
+  const choices = values.filter(item => item.toLowerCase().includes(filter.toLowerCase()))
+  // active index accounts for optional empty row at top
+  const optionCount = (allowEmpty ? 1 : 0) + choices.length
+  const closedDisplay = value || (allowEmpty ? emptyText : '')
+
+  useEffect(() => {
+    const close = (event: MouseEvent) => {
+      if (!root.current?.contains(event.target as Node)) setOpen(false)
+    }
+    document.addEventListener('mousedown', close)
+    return () => document.removeEventListener('mousedown', close)
+  }, [])
+
+  function choose(next: string) {
+    onChange(next)
+    setFilter('')
+    setActive(0)
+    setOpen(false)
+  }
+
+  function onKeyDown(event: React.KeyboardEvent<HTMLInputElement>) {
+    if (event.key === 'Escape') setOpen(false)
+    if (event.key === 'ArrowDown') {
+      event.preventDefault()
+      setActive(current => Math.max(0, Math.min(current + 1, optionCount - 1)))
+    }
+    if (event.key === 'ArrowUp') {
+      event.preventDefault()
+      setActive(current => Math.max(0, current - 1))
+    }
+    if (event.key === 'Enter' && open) {
+      event.preventDefault()
+      if (allowEmpty && active === 0) choose('')
+      else {
+        const item = choices[allowEmpty ? active - 1 : active]
+        if (item) choose(item)
+      }
+    }
+  }
+
+  return (
+    <div ref={root} className={cn('relative min-w-48', className)}>
+      {!hideLabel && label ? (
+        <label className="mb-1 block text-sm font-medium" htmlFor={id}>{label}</label>
+      ) : null}
+      <Input
+        id={id}
+        role="combobox"
+        aria-label={hideLabel ? (ariaLabel ?? label) : undefined}
+        aria-autocomplete="list"
+        aria-expanded={open}
+        aria-controls={`${id}-options`}
+        disabled={disabled}
+        value={open ? filter : closedDisplay}
+        placeholder={placeholder ?? t('select.placeholder')}
+        className={cn('h-9', triggerClassName)}
+        onFocus={() => { setFilter(''); setOpen(true) }}
+        onChange={event => { setFilter(event.target.value); setActive(0); setOpen(true) }}
+        onKeyDown={onKeyDown}
+      />
+      {open && (
+        <div id={`${id}-options`} role="listbox" className="absolute z-30 mt-1 max-h-56 w-full overflow-auto rounded-md border bg-popover p-1 shadow-lg">
+          {allowEmpty && (
+            <button
+              type="button"
+              role="option"
+              aria-selected={!value}
+              className={cn('block w-full rounded px-2 py-1.5 text-left text-sm hover:bg-muted', active === 0 && 'bg-primary/10 text-primary')}
+              onMouseDown={event => event.preventDefault()}
+              onClick={() => choose('')}
+            >
+              {emptyText}
+            </button>
+          )}
+          {loading ? (
+            <p className="px-2 py-1.5 text-sm text-muted-foreground">{t('select.loading')}</p>
+          ) : choices.length === 0 ? (
+            <p className="px-2 py-1.5 text-sm text-muted-foreground">{t('select.noMatch')}</p>
+          ) : (
+            choices.slice(0, 200).map((item, index) => {
+              const optionIndex = (allowEmpty ? 1 : 0) + index
+              return (
+                <button
+                  key={item}
+                  type="button"
+                  role="option"
+                  aria-selected={item === value}
+                  className={cn(
+                    'block w-full rounded px-2 py-1.5 text-left text-sm',
+                    optionIndex === active ? 'bg-primary/10 text-primary' : 'hover:bg-muted',
+                  )}
+                  onMouseDown={event => event.preventDefault()}
+                  onClick={() => choose(item)}
+                >
+                  {item}
+                </button>
+              )
+            })
+          )}
+        </div>
+      )}
+    </div>
+  )
+}
+
+export default SearchableValueSelect
diff --git a/frontend/src/components/index.ts b/frontend/src/components/index.ts
index db85a09..76c2ac0 100644
--- a/frontend/src/components/index.ts
+++ b/frontend/src/components/index.ts
@@ -16,3 +16,4 @@ export { getStatusColorClass } from './status-config';
 export { default as ErrorBoundary } from './ErrorBoundary';
 export { TimeRangePicker } from './TimeRangePicker';
 export { StatCard } from './StatCard';
+export { SearchableValueSelect } from './SearchableValueSelect'
diff --git a/frontend/src/pages/analysis/index.tsx b/frontend/src/pages/analysis/index.tsx
index 093aa42..9b7c224 100644
--- a/frontend/src/pages/analysis/index.tsx
+++ b/frontend/src/pages/analysis/index.tsx
@@ -4,6 +4,8 @@ import { useTranslation } from 'react-i18next'
 import '@/i18n/domains'
 import { BarChart3, Boxes, FileWarning, Loader2, RefreshCw, ScrollText, TriangleAlert } from 'lucide-react'
 import { Button } from '@/components/ui/button'
+import { Select, SelectContent, SelectItem, SelectTrigger, SelectValue } from '@/components/ui/select'
+import { SearchableValueSelect } from '@/components/SearchableValueSelect'
 import { Card, CardContent, CardHeader, CardTitle } from '@/components/ui/card'
 import { PageContainer } from '@/components/PageContainer'
 import { EmptyState } from '@/components/EmptyState'
@@ -35,6 +37,7 @@ const AnalysisPage = memo(function AnalysisPage() {
   const [sources, setSources] = useState<LogSource[]>([])
   const [sourceId, setSourceId] = useState(0)
   const [namespaces, setNamespaces] = useState<string[]>([])
+  const [namespacesLoading, setNamespacesLoading] = useState(false)
   const [namespace, setNamespace] = useState('')
   const [start, setStart] = useState(() => toLocal(new Date(Date.now() - 3600000)))
   const [end, setEnd] = useState(() => toLocal(new Date()))
@@ -53,11 +56,17 @@ const AnalysisPage = memo(function AnalysisPage() {
   }, [])
   // 命名空间候选随数据源变化(切换数据源时在 onChange 里同步清掉已选命名空间)
   useEffect(() => {
-    if (!sourceId) return
+    if (!sourceId) {
+      setNamespaces([])
+      setNamespacesLoading(false)
+      return
+    }
     let active = true
+    setNamespacesLoading(true)
     logsApi.labelValues(sourceId, 'namespace')
       .then(list => { if (active) setNamespaces(Array.isArray(list) ? list : []) })
       .catch(() => { if (active) setNamespaces([]) })
+      .finally(() => { if (active) setNamespacesLoading(false) })
     return () => { active = false }
   }, [sourceId])
 
@@ -87,25 +96,32 @@ const AnalysisPage = memo(function AnalysisPage() {
     >
       {/* 筛选栏:数据源 / 命名空间 / 时间范围 */}
       <div className="flex flex-wrap items-center gap-2">
-        <select
-          aria-label={t('filter.source')}
-          className="h-9 min-w-40 rounded-md border bg-background px-3 text-sm text-foreground"
-          value={sourceId}
-          onChange={event => { setSourceId(Number(event.target.value)); setNamespace('') }}
+        <Select
+          value={sourceId ? String(sourceId) : undefined}
+          onValueChange={value => { setSourceId(Number(value)); setNamespace('') }}
+          disabled={sources.length === 0}
         >
-          {sources.length === 0 && <option value={0}>{t('filter.sourceEmpty')}</option>}
-          {sources.map(source => <option key={source.id} value={source.id}>{source.name}</option>)}
-        </select>
-        <select
-          aria-label={t('filter.namespace')}
-          className="h-9 min-w-36 rounded-md border bg-background px-3 text-sm text-foreground"
+          <SelectTrigger className="h-9 min-w-40" aria-label={t('filter.source')}>
+            <SelectValue placeholder={t('filter.sourceEmpty')} />
+          </SelectTrigger>
+          <SelectContent>
+            {sources.map(source => (
+              <SelectItem key={source.id} value={String(source.id)}>{source.name}</SelectItem>
+            ))}
+          </SelectContent>
+        </Select>
+        <SearchableValueSelect
+          hideLabel
+          ariaLabel={t('filter.namespace')}
+          values={namespaces}
           value={namespace}
-          onChange={event => setNamespace(event.target.value)}
+          onChange={setNamespace}
+          allowEmpty
+          emptyLabel={t('filter.allNamespaces')}
+          loading={namespacesLoading}
           disabled={!sourceId}
-        >
-          <option value="">{t('filter.allNamespaces')}</option>
-          {namespaces.map(item => <option key={item} value={item}>{item}</option>)}
-        </select>
+          className="min-w-36"
+        />
         <TimeRangePicker start={start} end={end} onChange={(nextStart, nextEnd) => { setStart(nextStart); setEnd(nextEnd) }} />
       </div>
 
diff --git a/frontend/src/pages/logs/components/SearchableValueSelect.tsx b/frontend/src/pages/logs/components/SearchableValueSelect.tsx
index 6caa848..2593411 100644
--- a/frontend/src/pages/logs/components/SearchableValueSelect.tsx
+++ b/frontend/src/pages/logs/components/SearchableValueSelect.tsx
@@ -1,68 +1 @@
-import { useEffect, useId, useRef, useState } from 'react'
-import { useTranslation } from 'react-i18next'
-import { Input } from '@/components/ui/input'
-
-interface SearchableValueSelectProps {
-  label: string
-  values: string[]
-  value: string
-  onChange: (value: string) => void
-  placeholder?: string
-  allowEmpty?: boolean
-  loading?: boolean
-  disabled?: boolean
-}
-
-/** A searchable single-value combobox for Loki label values. */
-export function SearchableValueSelect({ label, values, value, onChange, placeholder, allowEmpty = false, loading = false, disabled = false }: SearchableValueSelectProps) {
-  const { t } = useTranslation('logs')
-  const [open, setOpen] = useState(false)
-  const [filter, setFilter] = useState('')
-  const [active, setActive] = useState(0)
-  const root = useRef<HTMLDivElement>(null)
-  const id = useId()
-  const choices = values.filter(item => item.toLowerCase().includes(filter.toLowerCase()))
-
-  useEffect(() => {
-    const close = (event: MouseEvent) => {
-      if (!root.current?.contains(event.target as Node)) setOpen(false)
-    }
-    document.addEventListener('mousedown', close)
-    return () => document.removeEventListener('mousedown', close)
-  }, [])
-
-  function choose(next: string) {
-    onChange(next)
-    setFilter('')
-    setActive(0)
-    setOpen(false)
-  }
-
-  return <div ref={root} className="relative min-w-48">
-    <label className="block text-sm font-medium mb-1" htmlFor={id}>{label}</label>
-    <Input
-      id={id}
-      role="combobox"
-      aria-autocomplete="list"
-      aria-expanded={open}
-      aria-controls={`${id}-options`}
-      disabled={disabled}
-      value={open ? filter : value}
-      placeholder={placeholder ?? t('select.placeholder')}
-      onFocus={() => { setFilter(''); setOpen(true) }}
-      onChange={event => { setFilter(event.target.value); setActive(0); setOpen(true) }}
-      onKeyDown={event => {
-        if (event.key === 'Escape') setOpen(false)
-        if (event.key === 'ArrowDown') { event.preventDefault(); setActive(current => Math.max(0, Math.min(current + 1, choices.length - 1))) }
-        if (event.key === 'ArrowUp') { event.preventDefault(); setActive(current => Math.max(0, current - 1)) }
-        if (event.key === 'Enter' && open && choices[active]) { event.preventDefault(); choose(choices[active]) }
-      }}
-    />
-    {open && <div id={`${id}-options`} role="listbox" className="absolute z-30 mt-1 max-h-56 w-full overflow-auto rounded-md border bg-popover p-1 shadow-lg">
-      {allowEmpty && <button type="button" role="option" aria-selected={!value} className="block w-full rounded px-2 py-1.5 text-left text-sm hover:bg-muted" onMouseDown={event => event.preventDefault()} onClick={() => choose('')}>{t('select.any')}</button>}
-      {loading ? <p className="px-2 py-1.5 text-sm text-muted-foreground">{t('select.loading')}</p> : choices.length === 0 ? <p className="px-2 py-1.5 text-sm text-muted-foreground">{t('select.noMatch')}</p> : choices.slice(0, 200).map((item, index) =>
-        <button key={item} type="button" role="option" aria-selected={item === value} className={`block w-full rounded px-2 py-1.5 text-left text-sm ${index === active ? 'bg-primary/10 text-primary' : 'hover:bg-muted'}`} onMouseDown={event => event.preventDefault()} onClick={() => choose(item)}>{item}</button>
-      )}
-    </div>}
-  </div>
-}
+export { SearchableValueSelect } from '@/components/SearchableValueSelect'
diff --git a/frontend/src/pages/logs/index.tsx b/frontend/src/pages/logs/index.tsx
index 84e862b..e2943d5 100644
--- a/frontend/src/pages/logs/index.tsx
+++ b/frontend/src/pages/logs/index.tsx
@@ -3,6 +3,7 @@ import { toast } from 'sonner'
 import { useTranslation } from 'react-i18next'
 import '@/i18n/domains'
 import { Button } from '@/components/ui/button'
+import { Select, SelectContent, SelectItem, SelectTrigger, SelectValue } from '@/components/ui/select'
 import { Input } from '@/components/ui/input'
 import { PageContainer } from '@/components/PageContainer'
 import { TimeRangePicker } from '@/components/TimeRangePicker'
@@ -178,7 +179,14 @@ export default function LogsPage() {
           </div>
         )}
         <div className="flex flex-wrap items-center gap-2">
-          <select aria-label={t('toolbar.sourceAria')} className="h-9 min-w-40 rounded-md border bg-background px-3 text-sm text-foreground" value={sourceId} onChange={event => setSourceId(Number(event.target.value))}>{sources.length === 0 && <option value={0}>{t('toolbar.sourceEmptyOption')}</option>}{sources.map(source => <option key={source.id} value={source.id}>{source.name}</option>)}</select>
+          <Select value={sourceId ? String(sourceId) : undefined} onValueChange={value => setSourceId(Number(value))} disabled={sources.length === 0}>
+            <SelectTrigger className="h-9 min-w-40" aria-label={t('toolbar.sourceAria')}>
+              <SelectValue placeholder={t('toolbar.sourceEmptyOption')} />
+            </SelectTrigger>
+            <SelectContent>
+              {sources.map(source => <SelectItem key={source.id} value={String(source.id)}>{source.name}</SelectItem>)}
+            </SelectContent>
+          </Select>
           <TimeRangePicker start={start} end={end} onChange={(nextStart, nextEnd) => { setStart(nextStart); setEnd(nextEnd); setTail(false) }} />
           <label className="flex items-center gap-1 text-xs text-muted-foreground">{t('toolbar.limitLabel')}<Input type="number" min={1} max={1000} value={limit} onChange={event => setLimit(Math.min(1000, Math.max(1, Number(event.target.value))))} className="h-9 w-24" /></label>
         </div>