diff --git a/README.md b/README.md
index 414ade8..420c38f 100644
--- a/README.md
+++ b/README.md
@@ -42,6 +42,7 @@ UI library.
 * [json-editor](./src/json-editor/README.md): JSON editor.
 * [keyboard](./src/keyboard/README.md): Virtual keyboard.
 * [log](./src/log/README.md): Terminal log viewer.
+* [logcat](./src/logcat/README.md): Android logcat viewer.
 * [markdown-editor](./src/markdown-editor/README.md): Markdown editor with preview.
 * [markdown-viewer](./src/markdown-viewer/README.md): Live markdown renderer.
 * [mask-editor](./src/mask-editor/README.md): Image mask editing.
diff --git a/index.json b/index.json
index 955af79..09821b8 100644
--- a/index.json
+++ b/index.json
@@ -162,12 +162,12 @@
     "react": false
   },
   "logcat": {
+    "react": true,
     "version": "0.1.0",
     "style": true,
     "icon": false,
     "test": true,
     "install": false,
-    "react": false,
     "dependencies": []
   },
   "lrc-player": {
diff --git a/src/logcat/README.md b/src/logcat/README.md
index 4432c9c..af4b996 100644
--- a/src/logcat/README.md
+++ b/src/logcat/README.md
@@ -25,3 +25,43 @@ npm install luna-logcat --save
 import 'luna-logcat/luna-logcat.css'
 import LunaLogcat from 'luna-logcat'
 ```
+
+## Usage
+
+```javascript
+const logcat = new LunaLogcat(container)
+logcatp.append({
+  date: '2021-01-01 00:00:00',
+  package: 'com.example',
+  pid: 1234,
+  tid: 1234,
+  priority: 3,
+  tag: 'tag',
+  message: 'message',
+})
+```
+
+## Configuration
+
+* entries(IEntry[]): Log entries.
+* filter(IFilter): Log filter.
+* maxNum(number): Max entry number, zero means infinite.
+* wrapLongLines(boolean): Wrap long lines.
+
+## Api
+
+### append(entry: IEntry): void
+
+Append entry.
+
+### clear(): void
+
+Clear all entries.
+
+## Types
+
+### IFilter
+
+* package(string): Package name.
+* priority(number): Entry priority.
+* tag(string): Tag name.
diff --git a/src/logcat/index.ts b/src/logcat/index.ts
index 26c0065..0a71733 100644
--- a/src/logcat/index.ts
+++ b/src/logcat/index.ts
@@ -6,11 +6,16 @@ import throttle from 'licia/throttle'
 import isDate from 'licia/isDate'
 import each from 'licia/each'
 import strHash from 'licia/strHash'
+import $ from 'licia/$'
+import lowerCase from 'licia/lowerCase'
+import contain from 'licia/contain'
 import dateFormat from 'licia/dateFormat'
 import { exportCjs } from '../share/util'
 
 /** IOptions */
 export interface IOptions extends IComponentOptions {
+  /** Max entry number, zero means infinite. */
+  maxNum?: number
   /** Log filter. */
   filter?: IFilter
   /** Log entries. */
@@ -19,8 +24,14 @@ export interface IOptions extends IComponentOptions {
   wrapLongLines?: boolean
 }
 
-interface IFilter {
+/** IFilter */
+export interface IFilter {
+  /** Entry priority. */
   priority?: number
+  /** Package name. */
+  package?: string
+  /** Tag name. */
+  tag?: string
 }
 
 interface IBaseEntry {
@@ -52,6 +63,7 @@ interface IEntry extends IBaseEntry {
  * })
  */
 export default class Logcat extends Component<IOptions> {
+  private isAtBottom = true
   private render: types.AnyFn
   private entries: Array<{
     container: HTMLElement
@@ -61,6 +73,7 @@ export default class Logcat extends Component<IOptions> {
     super(container, { compName: 'logcat' })
 
     this.initOptions(options, {
+      maxNum: 0,
       entries: [],
       wrapLongLines: false,
     })
@@ -78,8 +91,14 @@ export default class Logcat extends Component<IOptions> {
 
     this.bindEvent()
   }
+  destroy() {
+    this.$container.off('scroll', this.onScroll)
+    super.destroy()
+  }
+  /** Append entry. */
   append(entry: IEntry) {
-    const { c } = this
+    const { c, entries } = this
+    const { maxNum } = this.options
 
     const date: Date = isDate(entry.date)
       ? (entry.date as Date)
@@ -92,11 +111,18 @@ export default class Logcat extends Component<IOptions> {
       ...entry,
       date,
     }
-    this.entries.push({
+    entries.push({
       container,
       entry: e,
     })
 
+    if (maxNum !== 0 && entries.length > maxNum) {
+      const entry = entries.shift()
+      if (entry) {
+        $(entry.container).remove()
+      }
+    }
+
     const html = [
       `<span class="${c('date')}">${dateFormat(
         date,
@@ -114,12 +140,23 @@ export default class Logcat extends Component<IOptions> {
 
     if (this.filterEntry(e)) {
       this.container.appendChild(container)
+      if (this.isAtBottom) {
+        this.scrollToBottom()
+      }
     }
   }
+  /** Clear all entries. */
   clear() {
     this.entries = []
     this.$container.html('')
   }
+  private scrollToBottom() {
+    const { container } = this
+    const { scrollHeight, scrollTop, offsetHeight } = container
+    if (scrollTop <= scrollHeight - offsetHeight) {
+      container.scrollTop = 10000000
+    }
+  }
   private filterEntry(entry: IBaseEntry) {
     const { filter } = this.options
 
@@ -131,12 +168,26 @@ export default class Logcat extends Component<IOptions> {
       return false
     }
 
+    if (filter.package) {
+      if (!contain(lowerCase(entry.package), lowerCase(filter.package))) {
+        return false
+      }
+    }
+
+    if (filter.tag) {
+      if (!contain(lowerCase(entry.tag), lowerCase(filter.tag))) {
+        return false
+      }
+    }
+
     return true
   }
   private bindEvent() {
     const { c } = this
 
     this.on('optionChange', (name, val) => {
+      const { entries } = this
+
       switch (name) {
         case 'wrapLongLines':
           if (val) {
@@ -145,21 +196,44 @@ export default class Logcat extends Component<IOptions> {
             this.$container.rmClass(c('wrap-long-lines'))
           }
           break
+        case 'maxNum':
+          if (val > 0 && entries.length > val) {
+            this.entries = entries.slice(entries.length - val)
+            this.render()
+          }
+          break
         case 'filter':
           this.render()
           break
       }
     })
+
+    this.$container.on('scroll', this.onScroll)
+  }
+  private onScroll = () => {
+    const { scrollHeight, offsetHeight, scrollTop } = this
+      .container as HTMLElement
+
+    let isAtBottom = false
+    if (scrollHeight === offsetHeight) {
+      isAtBottom = true
+    } else if (Math.abs(scrollHeight - offsetHeight - scrollTop) < 1) {
+      isAtBottom = true
+    }
+    this.isAtBottom = isAtBottom
   }
   private _render() {
     const { container } = this
     this.$container.html('')
+    this.isAtBottom = true
 
     each(this.entries, (entry) => {
       if (this.filterEntry(entry.entry)) {
         container.appendChild(entry.container)
       }
     })
+
+    this.scrollToBottom()
   }
 }
 
diff --git a/src/logcat/package.json b/src/logcat/package.json
index 044551e..b84d6bf 100644
--- a/src/logcat/package.json
+++ b/src/logcat/package.json
@@ -1,5 +1,8 @@
 {
   "name": "logcat",
   "version": "0.1.0",
-  "description": "Android logcat viewer"
+  "description": "Android logcat viewer",
+  "luna": {
+    "react": true
+  }
 }
diff --git a/src/logcat/react.tsx b/src/logcat/react.tsx
new file mode 100644
index 0000000..94ccfa7
--- /dev/null
+++ b/src/logcat/react.tsx
@@ -0,0 +1,46 @@
+import { CSSProperties, FC, useEffect, useRef } from 'react'
+import each from 'licia/each'
+import Logcat, { IOptions } from './index'
+import { useNonInitialEffect } from '../share/hooks'
+
+interface IILogcatProps extends IOptions {
+  style?: CSSProperties
+  className?: string
+  onCreate?: (logcat: Logcat) => void
+}
+
+const LunaLogcat: FC<IILogcatProps> = (props) => {
+  const logcatRef = useRef<HTMLDivElement>(null)
+  const logcat = useRef<Logcat>()
+
+  useEffect(() => {
+    const { maxNum, wrapLongLines, filter, entries } = props
+    logcat.current = new Logcat(logcatRef.current!, {
+      filter,
+      maxNum,
+      wrapLongLines,
+      entries,
+    })
+    props.onCreate && props.onCreate(logcat.current)
+
+    return () => logcat.current?.destroy()
+  }, [])
+
+  each(['filter', 'maxNum', 'wrapLongLines'], (key: keyof IOptions) => {
+    useNonInitialEffect(() => {
+      if (logcat.current) {
+        logcat.current.setOption(key, props[key])
+      }
+    }, [props[key]])
+  })
+
+  return (
+    <div
+      className={props.className || ''}
+      ref={logcatRef}
+      style={props.style}
+    ></div>
+  )
+}
+
+export default LunaLogcat
diff --git a/src/logcat/story.js b/src/logcat/story.js
index 7781377..397526c 100644
--- a/src/logcat/story.js
+++ b/src/logcat/story.js
@@ -4,7 +4,8 @@ import readme from './README.md'
 import story from '../share/story'
 import each from 'licia/each'
 import $ from 'licia/$'
-import { boolean, number, select } from '@storybook/addon-knobs'
+import { boolean, number, select, text } from '@storybook/addon-knobs'
+import LunaLogcat from './react'
 import logs from './logcat.json'
 
 const def = story(
@@ -12,10 +13,11 @@ const def = story(
   (container) => {
     $(container).css('height', '500px')
 
-    const { wrapLongLines, filter } = createKnobs()
+    const { wrapLongLines, maxNum, filter } = createKnobs()
 
     const logcat = new Logcat(container, {
       filter,
+      maxNum,
       wrapLongLines,
     })
     each(logs, (log) => logcat.append(log))
@@ -25,6 +27,19 @@ const def = story(
   {
     readme,
     story: __STORY__,
+    ReactComponent() {
+      const { wrapLongLines, maxNum, filter } = createKnobs()
+
+      return (
+        <LunaLogcat
+          style={{ height: '500px' }}
+          wrapLongLines={wrapLongLines}
+          maxNum={maxNum}
+          filter={filter}
+          onCreate={(logcat) => each(logs, (log) => logcat.append(log))}
+        />
+      )
+    },
   }
 )
 
@@ -40,15 +55,26 @@ function createKnobs() {
     },
     1
   )
+  const filterPackage = text('Filter Package', '')
+  const filterTag = text('Filter Tag', '')
+  const maxNum = number('Max Number', 500, {
+    range: true,
+    min: 10,
+    max: 1000,
+    step: 10,
+  })
   const wrapLongLines = boolean('Wrap Long Lines', false)
 
   return {
     filter: {
       priority: filterPriority,
+      package: filterPackage,
+      tag: filterTag,
     },
+    maxNum,
     wrapLongLines,
   }
 }
 
 export default def
-export const { logcat } = def
+export const { logcat: html, react } = def