diff --git a/backend/controllers/logs.go b/backend/controllers/logs.go
index bf85d0b..7539718 100644
--- a/backend/controllers/logs.go
+++ b/backend/controllers/logs.go
@@ -16,6 +16,24 @@ import (
 	"github.com/gin-gonic/gin"
 )
 
+// 上下文前后条数的默认值与上限（原来是硬编码 5）
+const (
+	DefaultContextLines = 2
+	MaxContextLines     = 50
+)
+
+// normalizeContextLines 把前端传入的条数收敛到 [1, MaxContextLines]，
+// 不传(0)或负数一律用默认值。
+func normalizeContextLines(n int) int {
+	if n <= 0 {
+		return DefaultContextLines
+	}
+	if n > MaxContextLines {
+		return MaxContextLines
+	}
+	return n
+}
+
 func (ctrl *LogsController) Context(c *gin.Context) {
 	var req dto.LogContextRequest
 	if !utils.BindAndValidate(c, &req) {
@@ -41,13 +59,26 @@ func (ctrl *LogsController) Context(c *gin.Context) {
 		utils.Forbidden(c, err.Error())
 		return
 	}
-	span := int64(5 * time.Minute)
-	before, err := services.QueryLokiLogs(c.Request.Context(), src, query, ts-span, ts-1, 5, "backward", "")
+	// 前后条数由前端传入（默认 2 条，上限 50 —— 再多一次弹窗就是几百条日志）
+	beforeN := normalizeContextLines(req.Before)
+	afterN := normalizeContextLines(req.After)
+
+	// 时间窗随条数自适应：原来固定 5 分钟，条数调大时 5 分钟可能装不下，
+	// 条数调小时又白扫一大片。按「每条 30s」估算，最少 1 分钟，最多 2 小时。
+	span := int64(time.Duration(max(beforeN, afterN)*30) * time.Second)
+	if span < int64(time.Minute) {
+		span = int64(time.Minute)
+	}
+	if span > int64(2*time.Hour) {
+		span = int64(2 * time.Hour)
+	}
+
+	before, err := services.QueryLokiLogs(c.Request.Context(), src, query, ts-span, ts-1, beforeN, "backward", "")
 	if err != nil {
 		utils.Error(c, 502, err.Error())
 		return
 	}
-	after, err := services.QueryLokiLogs(c.Request.Context(), src, query, ts+1, ts+span, 5, "forward", "")
+	after, err := services.QueryLokiLogs(c.Request.Context(), src, query, ts+1, ts+span, afterN, "forward", "")
 	if err != nil {
 		utils.Error(c, 502, err.Error())
 		return
diff --git a/backend/dto/logs.go b/backend/dto/logs.go
index 0291952..272d800 100644
--- a/backend/dto/logs.go
+++ b/backend/dto/logs.go
@@ -45,4 +45,8 @@ type LogContextRequest struct {
 	SourceID    uint              `json:"sourceId" binding:"required"`
 	TimestampNs string            `json:"timestampNs" binding:"required"`
 	Labels      map[string]string `json:"labels" binding:"required"`
+	// 上下文前后各取几条（可选）。不传按 DefaultContextLines，
+	// 上限 MaxContextLines —— 原来前后各 5 条是写死的，不能调。
+	Before int `json:"before"`
+	After  int `json:"after"`
 }
diff --git a/frontend/src/api/logs/index.ts b/frontend/src/api/logs/index.ts
index d8e23c7..ebe85fb 100644
--- a/frontend/src/api/logs/index.ts
+++ b/frontend/src/api/logs/index.ts
@@ -29,7 +29,9 @@ export const logsApi = {
   // 否则旧请求会在后端继续占用 Loki CPU（历史上把实例拖到 OOM/不 Ready）。
   query: (data: LogQuery, opts?: { signal?: AbortSignal }) =>
     http.post<LogResult>('/logs/query', data, { timeout: 60000, ...opts }),
-  context: (data: { sourceId: number; timestampNs: string; labels: Record<string, string> }) => http.post<{ before: LogEntry[]; after: LogEntry[] }>('/logs/context', data),
+  /** 日志上下文：before/after 为前后各取几条（后端默认 2、上限 50，原来写死 5） */
+  context: (data: { sourceId: number; timestampNs: string; labels: Record<string, string>; before?: number; after?: number }) =>
+    http.post<{ before: LogEntry[]; after: LogEntry[] }>('/logs/context', data),
   /** 总量统计（Loki index/stats，只读索引）：用于计算总页数 */
   stats: (data: LogQuery, opts?: { signal?: AbortSignal }) =>
     http.post<{ streams: number; chunks: number; bytes: number; entries: number }>(
diff --git a/frontend/src/i18n/locales/en/logs.ts b/frontend/src/i18n/locales/en/logs.ts
index a39d6b6..c09308a 100644
--- a/frontend/src/i18n/locales/en/logs.ts
+++ b/frontend/src/i18n/locales/en/logs.ts
@@ -200,9 +200,10 @@ export default {
   },
   context: {
     title: 'Context of the same log stream',
+    linesLabel: 'Lines:',
     sameFile: 'Same file',
     sameStream: 'Same log stream',
-    meta: 'Up to 5 entries before and after · ±5 minutes',
+    meta: 'Same log stream, in time order',
     file: 'File: {{name}}',
     current: 'Current',
     currentAria: 'Current log',
diff --git a/frontend/src/i18n/locales/zh/logs.ts b/frontend/src/i18n/locales/zh/logs.ts
index ad17df6..58a2e97 100644
--- a/frontend/src/i18n/locales/zh/logs.ts
+++ b/frontend/src/i18n/locales/zh/logs.ts
@@ -196,9 +196,10 @@ export default {
   },
   context: {
     title: '同一日志流的前后文',
+    linesLabel: '前后各',
     sameFile: '同一文件',
     sameStream: '同一日志流',
-    meta: '前后各最多 5 条 · 前后 5 分钟',
+    meta: '同一条日志流，按时间顺序排列',
     file: '文件: {{name}}',
     current: '当前日志',
     currentAria: '当前日志',
diff --git a/frontend/src/pages/logs/components/LogContextDialog.tsx b/frontend/src/pages/logs/components/LogContextDialog.tsx
index f41bdac..4312dc5 100644
--- a/frontend/src/pages/logs/components/LogContextDialog.tsx
+++ b/frontend/src/pages/logs/components/LogContextDialog.tsx
@@ -1,6 +1,7 @@
 import { Crosshair } from 'lucide-react'
 import { useTranslation } from 'react-i18next'
 import { Dialog, DialogContent, DialogDescription, DialogHeader, DialogTitle } from '@/components/ui/dialog'
+import { Select, SelectContent, SelectItem, SelectTrigger, SelectValue } from '@/components/ui/select'
 import type { LogEntry } from '@/api/logs'
 import { HighlightedLogLine } from './HighlightedLogLine'
 
@@ -20,13 +21,31 @@ function ContextRow({ row, current, terms }: { row: LogEntry; current?: boolean;
   </article>
 }
 
-export function LogContextDialog({ context, terms, onClose }: { context: LogContext | null; terms: string[]; onClose: () => void }) {
+export function LogContextDialog({ context, terms, lines, onLinesChange, onClose }: {
+  context: LogContext | null
+  terms: string[]
+  /** 前后各取几条（原来是写死的 5 条） */
+  lines: number
+  onLinesChange: (lines: number) => void
+  onClose: () => void
+}) {
   const { t } = useTranslation('logs')
   return <Dialog open={context !== null} onOpenChange={open => { if (!open) onClose() }}>
     <DialogContent className="flex max-h-[85vh] flex-col gap-0 !overflow-hidden p-0 sm:max-w-4xl">
       <DialogHeader className="border-b px-5 py-4 pr-12">
         <DialogTitle>{t('context.title')}</DialogTitle>
-        <DialogDescription>{context?.row.labels.filename ? t('context.sameFile') : t('context.sameStream')} · {t('context.meta')}</DialogDescription>
+        <DialogDescription className="flex flex-wrap items-center gap-2">
+          <span>{context?.row.labels.filename ? t('context.sameFile') : t('context.sameStream')} · {t('context.meta')}</span>
+          <span className="inline-flex items-center gap-1">
+            {t('context.linesLabel')}
+            <Select value={String(lines)} onValueChange={value => onLinesChange(Number(value))}>
+              <SelectTrigger className="h-6 w-16 px-2 text-xs"><SelectValue /></SelectTrigger>
+              <SelectContent>
+                {[2, 5, 10, 20, 50].map(value => <SelectItem key={value} value={String(value)}>{value}</SelectItem>)}
+              </SelectContent>
+            </Select>
+          </span>
+        </DialogDescription>
         {context && <div className="flex flex-wrap gap-1.5 pt-1 text-xs">
           {['namespace', 'app', 'pod'].filter(key => context.row.labels[key]).map(key => <span key={key} className="rounded bg-muted px-2 py-1 font-mono text-foreground">{key}={context.row.labels[key]}</span>)}
           {context.row.labels.filename && <span title={context.row.labels.filename} className="max-w-full truncate rounded bg-muted px-2 py-1 font-mono text-foreground">{t('context.file', { name: context.row.labels.filename.split('/').slice(-2).join('/') })}</span>}
diff --git a/frontend/src/pages/logs/index.tsx b/frontend/src/pages/logs/index.tsx
index 03a0b7f..3ea23fe 100644
--- a/frontend/src/pages/logs/index.tsx
+++ b/frontend/src/pages/logs/index.tsx
@@ -4,7 +4,6 @@ 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'
 import { ErrorState } from '@/components/ErrorState'
@@ -199,12 +198,31 @@ export default function LogsPage() {
     return () => window.clearInterval(timer)
   }, [tail, sourceId, query, limit])
 
-  async function showContext(row: LogEntry) {
+  /** 上下文前后条数：默认 2 条（原来写死 5），选择后记住，弹窗内可随时改 */
+  const [contextLines, setContextLines] = useState<number>(() => {
+    const saved = Number(localStorage.getItem('logContextLines'))
+    return saved > 0 && saved <= 50 ? saved : 2
+  })
+  /** 记住当前查看上下文的那一行，切换条数时原地重新拉取 */
+  const [contextRow, setContextRow] = useState<LogEntry | null>(null)
+
+  async function showContext(row: LogEntry, lines = contextLines) {
+    setContextRow(row)
     try {
-      const result = await logsApi.context({ sourceId, timestampNs: row.timestampNs, labels: row.labels })
+      const result = await logsApi.context({
+        sourceId, timestampNs: row.timestampNs, labels: row.labels,
+        before: lines, after: lines,
+      })
       setContext({ row, before: result.before.slice().reverse(), after: result.after })
     } catch (e) { toast.error(e instanceof Error ? e.message : t('context.loadFailed')) }
   }
+
+  /** 改前后条数：持久化 + 若弹窗开着就原地刷新 */
+  const changeContextLines = (lines: number) => {
+    setContextLines(lines)
+    try { localStorage.setItem('logContextLines', String(lines)) } catch { /* 隐私模式忽略 */ }
+    if (contextRow) void showContext(contextRow, lines)
+  }
   const highlightTerms = useMemo(() => literalFilters(executedQuery), [executedQuery])
   const applyDomainFilter = (domain: string) => {
     const nextQuery = `${query.trim()} |= ${JSON.stringify(domain)}`
@@ -251,7 +269,14 @@ export default function LogsPage() {
             </SelectContent>
           </Select>
           <TimeRangePicker start={start} end={end} onChange={(nextStart, nextEnd) => { setStart(nextStart); setEnd(nextEnd); setTail(false) }} />
-          <label className="flex items-center gap-1 text-xs text-muted-foreground">{t('toolbar.limitLabel')}<Input type="number" min={1} max={1000} value={limit} onChange={event => setLimit(Math.min(1000, Math.max(1, Number(event.target.value))))} className="h-9 w-24" /></label>
+          <label className="flex items-center gap-1 text-xs text-muted-foreground">{t('toolbar.limitLabel')}
+            <Select value={String(limit)} onValueChange={value => setLimit(Number(value))}>
+              <SelectTrigger className="h-9 w-24" aria-label={t('toolbar.limitLabel')}><SelectValue /></SelectTrigger>
+              <SelectContent>
+                {[100, 500, 1000, 2000, 5000].map(value => <SelectItem key={value} value={String(value)}>{value}</SelectItem>)}
+              </SelectContent>
+            </Select>
+          </label>
         </div>
         <div className="flex flex-wrap items-center gap-2">
           <span className="flex h-10 items-center gap-2 rounded-md border bg-muted/40 px-3 text-sm font-semibold text-info"><span className="size-2 rounded-full bg-info" />LogQL</span>
@@ -268,7 +293,7 @@ export default function LogsPage() {
       {tab === 'query' && histogramError && <p className="rounded-xl border bg-card p-4 text-sm text-muted-foreground">{histogramError}</p>}
       {tab === 'query' && buckets.length > 0 && <LogVolumeTimeline key={`${buckets[0].timestamp}-${buckets.length}`} buckets={buckets} onSelect={selectTimeRange} />}
       {tab === 'query' && <LogResultsPanel key={`${sourceId}:${executedQuery}:${executedRange?.start}:${executedRange?.end}`} entries={entries} searched={searched} hasSource={sources.length > 0} pageIndex={pageIndex} hasNextPage={Boolean(cursor)} totalPages={totalEntries > 0 ? Math.max(1, Math.ceil(totalEntries / Math.max(1, limit))) : undefined} loading={loading} loadingStartedAt={loadingStartedAt} query={query} terms={highlightTerms} onQueryChange={setQuery} onApplyDomain={applyDomainFilter} onShowContext={row => void showContext(row)} onSearch={() => void search()} onNextPage={() => void search(cursor, false, undefined, undefined, pageIndex + 1)} onPreviousPage={() => void search(pageCursors[pageIndex - 1] ?? '', false, undefined, undefined, pageIndex - 1)} />}
-      <LogContextDialog context={context} terms={highlightTerms} onClose={() => setContext(null)} />
+      <LogContextDialog context={context} terms={highlightTerms} lines={contextLines} onLinesChange={changeContextLines} onClose={() => { setContext(null); setContextRow(null) }} />
     </div>
       </PageContainer>
     </div>