diff --git a/preload/index.main.ts b/preload/index.main.ts
index bbd78e8..178376c 100644
--- a/preload/index.main.ts
+++ b/preload/index.main.ts
@@ -1,16 +1,20 @@
 import fs from 'fs'
 import path from 'path'
 import { contextBridge, ipcRenderer } from 'electron'
-import { domReady } from './utils'
+import { domReady, injectWsCode } from './utils'
 import { useLoading } from './loading'
 
+const isDev = process.env.NODE_ENV === 'development'
 const { appendLoading, removeLoading } = useLoading()
 
-
 ; (async () => {
   await domReady()
 
   appendLoading()
+  isDev && injectWsCode({
+    host: '127.0.0.1',
+    port: process.env.PORT_WS as string,
+  })
 })();
 
 // ---------------------------------------------------
diff --git a/preload/utils.ts b/preload/utils.ts
index 7dd3280..5405abf 100644
--- a/preload/utils.ts
+++ b/preload/utils.ts
@@ -13,3 +13,37 @@ export function domReady(condition: DocumentReadyState[] = ['complete', 'interac
     }
   })
 }
+
+/** Inject ws related code */
+export function injectWsCode(options: {
+  host: string
+  port: string | number
+}) {
+  const oScript = document.createElement('script')
+  oScript.id = 'ws-preload-hot-reload'
+
+  oScript.innerHTML = `
+${__ws_hot_reload_for_preload.toString()}
+${__ws_hot_reload_for_preload.name}(${JSON.stringify(options)})
+`
+
+  document.body.appendChild(oScript)
+}
+
+function __ws_hot_reload_for_preload(options: { host: string; port: string | number }) {
+  const ws = new WebSocket(`ws://${options.host}:${options.port}`)
+  ws.onmessage = function (ev) {
+    try {
+      console.log('[preload] ws.onmessage:', ev.data)
+
+      const data = JSON.parse(ev.data) // { "cmd": "string", data: "string|number" }
+
+      if (data.cmd === 'reload') {
+        setTimeout(() => window.location.reload(), 999)
+      }
+    } catch (error) {
+      console.warn(`ws.onmessage should be accept "JSON.string" formatted string.`)
+      console.error(error)
+    }
+  }
+}
diff --git a/scripts/dev.ts b/scripts/dev.ts
index 5386765..a908d46 100644
--- a/scripts/dev.ts
+++ b/scripts/dev.ts
@@ -1,21 +1,26 @@
+process.env.NODE_ENV = 'development'
+
 import { join } from 'path'
-import { spawn, ChildProcess } from 'child_process'
 import electron from 'electron'
-import { RollupWatcher, RollupWatcherEvent, watch } from 'rollup'
+import { spawn, ChildProcess } from 'child_process'
 import { createServer as createViteServer } from 'vite'
+import { RollupWatcher, RollupWatcherEvent, watch } from 'rollup'
+import WebSocket from 'ws'
+import chalk from 'chalk'
 import pkg from '../package.json'
 import {
   mainOptions,
   preloadOptions,
 } from './utils'
+import { createWsServer, formatWsSendData } from './ws'
 
-const TAG = '[dev.ts]'
+const TAG = chalk.bgGray('[dev.ts]')
 
 function eventHandle(ev: RollupWatcherEvent) {
   if (ev.code === 'ERROR') {
-    console.error(TAG, ev.error)
+    console.error(TAG, chalk.red(ev.error))
   } else if (ev.code === 'BUNDLE_START') {
-    console.log(TAG, `Rebuild - ${ev.output}`)
+    console.log(TAG, chalk.blue(`Rebuild - ${ev.output}`))
   }
 }
 
@@ -41,10 +46,16 @@ function watchMain(): RollupWatcher {
 }
 
 function watchPreload(): RollupWatcher {
+  const wssObj = createWsServer({ TAG })
+
   return watch(preloadOptions())
     .on('event', ev => {
       if (ev.code === 'END') {
-        // TODO Hot reload
+        // Hot reload renderer process !!!
+        if (wssObj.instance?.readyState === WebSocket.OPEN) {
+          console.log(TAG, chalk.yellow('Hot reload renderer process'))
+          wssObj.instance.send(formatWsSendData({ cmd: 'reload', data: Date.now() }))
+        }
       }
 
       eventHandle(ev)
@@ -59,11 +70,11 @@ function watchPreload(): RollupWatcher {
     })).listen()
     const { host = '127.0.0.1', port = 3000 } = server.config.server
 
-    console.log(TAG, `Server run at - http://${host}:${port}`)
+    console.log(TAG, chalk.yellow(`Server run at - http://${host}:${port}`))
 
     watchPreload()
     watchMain()
   } catch (error) {
-    console.error(TAG, error)
+    console.error(TAG, chalk.red(error))
   }
 })();
diff --git a/scripts/ws.ts b/scripts/ws.ts
new file mode 100644
index 0000000..c00e6f9
--- /dev/null
+++ b/scripts/ws.ts
@@ -0,0 +1,43 @@
+/**
+ * Hot reload from preload script during development
+ */
+import WebSocket from 'ws'
+import chalk from 'chalk'
+import pkg from '../package.json'
+
+export interface CreateWsServerOptions {
+  TAG: string
+}
+
+export function createWsServer(options: CreateWsServerOptions) {
+  const { TAG } = options
+  const port = pkg.env.PORT_WS
+  const host = pkg.env.HOST || '127.0.0.1'
+  const wss = new WebSocket.Server({ host, port })
+  const wssObj: { wss: WebSocket.Server; instance: WebSocket | null } = { wss, instance: null }
+
+  console.log(TAG, 'Wss run at - ' + chalk.yellow(`ws://${host}:${port}`))
+
+  wss.on('connection', ws => {
+    console.log(TAG, chalk.yellow(`wss.on('connection')`))
+
+    wssObj.instance = ws
+    ws.on('message', message => {
+      console.log(TAG, `ws.on('message'):`, message.toString())
+    })
+
+    ws.send(formatWsSendData({ cmd: 'message', data: 'connected.' }))
+  })
+
+  wss.on('close', () => {
+    console.log(TAG, chalk.gray(`wss.on('close')`))
+
+    wssObj.instance = null
+  })
+
+  return wssObj
+}
+
+export function formatWsSendData(json: { cmd: string, data?: any }) {
+  return JSON.stringify(json)
+}