diff --git a/README.md b/README.md
index 4b3ee698..c0a227d9 100644
--- a/README.md
+++ b/README.md
@@ -120,11 +120,11 @@ Load app/extend/helper.js
 
 #### loadCustomApp
 
-Load app.js
+Load app.js, if app.js export boot class, then trigger configDidLoad
 
 #### loadCustomAgent
 
-Load agent.js
+Load agent.js, if agent.js export boot class, then trigger configDidLoad
 
 #### loadService
 
diff --git a/lib/lifecycle.js b/lib/lifecycle.js
index e917d310..1543c57b 100644
--- a/lib/lifecycle.js
+++ b/lib/lifecycle.js
@@ -80,6 +80,19 @@ class Lifecycle extends EventEmitter {
     this[BOOT_HOOKS].push(hook);
   }
 
+  addFunctionAsBootHook(hook) {
+    // app.js is export as a funciton
+    // call this function in configDidLoad
+    this[BOOT_HOOKS].push(class Hook {
+      constructor(app) {
+        this.app = app;
+      }
+      configDidLoad() {
+        hook(this.app);
+      }
+    });
+  }
+
   /**
    * init boots and trigger config did config
    */
diff --git a/lib/loader/egg_loader.js b/lib/loader/egg_loader.js
index 190aaa29..dea654dc 100644
--- a/lib/loader/egg_loader.js
+++ b/lib/loader/egg_loader.js
@@ -95,10 +95,6 @@ class EggLoader {
       : this.getServerScope();
   }
 
-  get bootFileName() {
-    return this.app.type === 'application' ? 'app' : 'agent';
-  }
-
   /**
    * Get {@link AppInfo#env}
    * @return {String} env
@@ -468,7 +464,6 @@ const loaders = [
   require('./mixin/middleware'),
   require('./mixin/controller'),
   require('./mixin/router'),
-  require('./mixin/boot'),
 ];
 
 for (const loader of loaders) {
diff --git a/lib/loader/mixin/boot.js b/lib/loader/mixin/boot.js
deleted file mode 100644
index 0fdba0d6..00000000
--- a/lib/loader/mixin/boot.js
+++ /dev/null
@@ -1,28 +0,0 @@
-'use strict';
-
-const path = require('path');
-const is = require('is-type-of');
-
-module.exports = {
-  /**
-   * load app.js/agent.js if it's a boot class
-   */
-  loadBootHook() {
-    const fileName = this.bootFileName;
-    this.timing.start(`Load boot/${fileName}.js`);
-    for (const unit of this.getLoadUnits()) {
-      const bootFilePath = this.resolveModule(path.join(unit.path, fileName));
-      if (!bootFilePath) {
-        continue;
-      }
-      const bootHook = this.requireFile(bootFilePath);
-      // if is boot class, add to lifecycle
-      if (is.class(bootHook)) {
-        this.lifecycle.addBootHook(bootHook);
-      }
-    }
-    // init boots
-    this.lifecycle.init();
-    this.timing.end(`Load boot/${fileName}.js`);
-  },
-};
diff --git a/lib/loader/mixin/custom.js b/lib/loader/mixin/custom.js
index df77674d..4999c964 100644
--- a/lib/loader/mixin/custom.js
+++ b/lib/loader/mixin/custom.js
@@ -1,41 +1,73 @@
 'use strict';
 
+const is = require('is-type-of');
 const path = require('path');
 
+const LOAD_BOOT_HOOK = Symbol('Loader#loadBootHook');
+
 module.exports = {
 
   /**
    * load app.js
    *
    * @example
+   * - old:
+   *
    * ```js
    * module.exports = function(app) {
-   *   // can do everything
-   *   do();
-   *
-   *   // if you will invoke asynchronous, you can use readyCallback
-   *   const done = app.readyCallback();
-   *   doAsync(done);
+   *   doSomething();
    * }
    * ```
+   *
+   * - new:
+   *
+   * ```js
+   * module.exports = class Boot {
+   *   constructor(app) {
+   *     this.app = app;
+   *   }
+   *   configDidLoad() {
+   *     doSomething();
+   *   }
+   * }
    * @since 1.0.0
    */
   loadCustomApp() {
-    this.timing.start('Load app.js');
+    this[LOAD_BOOT_HOOK]('app');
     this.lifecycle.triggerConfigDidLoad();
-    this.getLoadUnits()
-      .forEach(unit => this.loadFile(this.resolveModule(path.join(unit.path, 'app'))));
-    this.timing.end('Load app.js');
   },
 
   /**
    * Load agent.js, same as {@link EggLoader#loadCustomApp}
    */
   loadCustomAgent() {
-    this.timing.start('Load agent.js');
+    this[LOAD_BOOT_HOOK]('agent');
     this.lifecycle.triggerConfigDidLoad();
-    this.getLoadUnits()
-      .forEach(unit => this.loadFile(this.resolveModule(path.join(unit.path, 'agent'))));
-    this.timing.end('Load agent.js');
+  },
+
+  // FIXME: no logger used after egg removed
+  loadBootHook() {
+    // do nothing
+  },
+
+  [LOAD_BOOT_HOOK](fileName) {
+    this.timing.start(`Load ${fileName}.js`);
+    for (const unit of this.getLoadUnits()) {
+      const bootFilePath = this.resolveModule(path.join(unit.path, fileName));
+      if (!bootFilePath) {
+        continue;
+      }
+      const bootHook = this.requireFile(bootFilePath);
+      if (is.class(bootHook)) {
+        // if is boot class, add to lifecycle
+        this.lifecycle.addBootHook(bootHook);
+      } else {
+        // if is boot function, wrap to class
+        this.lifecycle.addFunctionAsBootHook(bootHook);
+      }
+    }
+    // init boots
+    this.lifecycle.init();
+    this.timing.end(`Load ${fileName}.js`);
   },
 };
diff --git a/test/egg.test.js b/test/egg.test.js
index 4783f014..547e8a52 100644
--- a/test/egg.test.js
+++ b/test/egg.test.js
@@ -569,15 +569,17 @@ describe('test/egg.test.js', () => {
           assert.deepStrictEqual(
             app.bootLog,
             [
-              'configDidLoad',
-              'app.js',
+              'configDidLoad in plugin',
+              'app.js in plugin',
+              'configDidLoad in app',
             ]);
           await app.ready();
           assert.deepStrictEqual(
             app.bootLog,
             [
-              'configDidLoad',
-              'app.js',
+              'configDidLoad in plugin',
+              'app.js in plugin',
+              'configDidLoad in app',
               'didLoad',
               'beforeStart',
               'willReady',
@@ -587,8 +589,9 @@ describe('test/egg.test.js', () => {
           assert.deepStrictEqual(
             app.bootLog,
             [
-              'configDidLoad',
-              'app.js',
+              'configDidLoad in plugin',
+              'app.js in plugin',
+              'configDidLoad in app',
               'didLoad',
               'beforeStart',
               'willReady',
@@ -600,8 +603,9 @@ describe('test/egg.test.js', () => {
           assert.deepStrictEqual(
             app.bootLog,
             [
-              'configDidLoad',
-              'app.js',
+              'configDidLoad in plugin',
+              'app.js in plugin',
+              'configDidLoad in app',
               'didLoad',
               'beforeStart',
               'willReady',
@@ -613,8 +617,9 @@ describe('test/egg.test.js', () => {
           assert.deepStrictEqual(
             app.bootLog,
             [
-              'configDidLoad',
-              'app.js',
+              'configDidLoad in plugin',
+              'app.js in plugin',
+              'configDidLoad in app',
               'didLoad',
               'beforeStart',
               'willReady',
@@ -632,20 +637,21 @@ describe('test/egg.test.js', () => {
           app.loader.loadPlugin();
           app.loader.loadConfig();
           app.loader.loadAgentExtend();
-          app.loader.loadBootHook();
           app.loader.loadCustomAgent();
           assert.deepStrictEqual(
             app.bootLog,
             [
-              'configDidLoad',
-              'app.js',
+              'configDidLoad in plugin',
+              'agent.js in plugin',
+              'configDidLoad in app',
             ]);
           await app.ready();
           assert.deepStrictEqual(
             app.bootLog,
             [
-              'configDidLoad',
-              'app.js',
+              'configDidLoad in plugin',
+              'agent.js in plugin',
+              'configDidLoad in app',
               'didLoad',
               'beforeStart',
               'willReady',
@@ -655,8 +661,9 @@ describe('test/egg.test.js', () => {
           assert.deepStrictEqual(
             app.bootLog,
             [
-              'configDidLoad',
-              'app.js',
+              'configDidLoad in plugin',
+              'agent.js in plugin',
+              'configDidLoad in app',
               'didLoad',
               'beforeStart',
               'willReady',
@@ -668,8 +675,9 @@ describe('test/egg.test.js', () => {
           assert.deepStrictEqual(
             app.bootLog,
             [
-              'configDidLoad',
-              'app.js',
+              'configDidLoad in plugin',
+              'agent.js in plugin',
+              'configDidLoad in app',
               'didLoad',
               'beforeStart',
               'willReady',
@@ -681,8 +689,9 @@ describe('test/egg.test.js', () => {
           assert.deepStrictEqual(
             app.bootLog,
             [
-              'configDidLoad',
-              'app.js',
+              'configDidLoad in plugin',
+              'agent.js in plugin',
+              'configDidLoad in app',
               'didLoad',
               'beforeStart',
               'willReady',
@@ -818,8 +827,9 @@ describe('test/egg.test.js', () => {
         assert.deepStrictEqual(
           app.bootLog,
           [
-            'configDidLoad',
-            'app.js',
+            'configDidLoad in plugin',
+            'app.js in plugin',
+            'configDidLoad in app',
             'didLoad',
             'beforeStart',
             'willReady',
@@ -832,8 +842,9 @@ describe('test/egg.test.js', () => {
         assert.deepStrictEqual(
           app.bootLog,
           [
-            'configDidLoad',
-            'app.js',
+            'configDidLoad in plugin',
+            'app.js in plugin',
+            'configDidLoad in app',
             'didLoad',
             'beforeStart',
             'willReady',
diff --git a/test/fixtures/boot/agent.js b/test/fixtures/boot/agent.js
index 833c1cf8..28a33d48 100644
--- a/test/fixtures/boot/agent.js
+++ b/test/fixtures/boot/agent.js
@@ -9,7 +9,7 @@ module.exports = class {
   }
 
   configDidLoad() {
-    this.app.bootLog.push('configDidLoad');
+    this.app.bootLog.push('configDidLoad in app');
   }
 
   async didLoad() {
diff --git a/test/fixtures/boot/app.js b/test/fixtures/boot/app.js
index 04ede162..34bdd425 100644
--- a/test/fixtures/boot/app.js
+++ b/test/fixtures/boot/app.js
@@ -9,7 +9,7 @@ module.exports = class {
   }
 
   configDidLoad() {
-    this.app.bootLog.push('configDidLoad');
+    this.app.bootLog.push('configDidLoad in app');
   }
 
   async didLoad() {
diff --git a/test/fixtures/boot/app/plugin/boot-plugin-dep/agent.js b/test/fixtures/boot/app/plugin/boot-plugin-dep/agent.js
new file mode 100644
index 00000000..17b698cc
--- /dev/null
+++ b/test/fixtures/boot/app/plugin/boot-plugin-dep/agent.js
@@ -0,0 +1,10 @@
+'use strict';
+
+module.exports = class Boot {
+  constructor(agent) {
+    this.agent = agent;
+  }
+  configDidLoad() {
+    this.agent.bootLog.push('configDidLoad in plugin');
+  }
+};
diff --git a/test/fixtures/boot/app/plugin/boot-plugin-dep/app.js b/test/fixtures/boot/app/plugin/boot-plugin-dep/app.js
new file mode 100644
index 00000000..1ce58721
--- /dev/null
+++ b/test/fixtures/boot/app/plugin/boot-plugin-dep/app.js
@@ -0,0 +1,10 @@
+'use strict';
+
+module.exports = class Boot {
+  constructor(app) {
+    this.app = app;
+  }
+  configDidLoad() {
+    this.app.bootLog.push('configDidLoad in plugin');
+  }
+};
diff --git a/test/fixtures/boot/app/plugin/boot-plugin-dep/package.json b/test/fixtures/boot/app/plugin/boot-plugin-dep/package.json
new file mode 100644
index 00000000..2632e4b6
--- /dev/null
+++ b/test/fixtures/boot/app/plugin/boot-plugin-dep/package.json
@@ -0,0 +1,9 @@
+{
+  "name": "bootPluginDep",
+  "eggPlugin": {
+    "name": "bootPluginDep",
+    "deps": [
+      "bootPuginDep"
+    ]
+  }
+}
diff --git a/test/fixtures/boot/app/plugin/boot-plugin/agent.js b/test/fixtures/boot/app/plugin/boot-plugin/agent.js
index 5a25f77b..7f8e0e69 100644
--- a/test/fixtures/boot/app/plugin/boot-plugin/agent.js
+++ b/test/fixtures/boot/app/plugin/boot-plugin/agent.js
@@ -1,14 +1,14 @@
 'use strict';
 const sleep = require('mz-modules/sleep');
 
-module.exports = app => {
-  app.bootLog.push('app.js');
-  app.beforeStart(async () => {
+module.exports = agent => {
+  agent.bootLog.push('agent.js in plugin');
+  agent.beforeStart(async () => {
     await sleep(5);
-    app.bootLog.push('beforeStart');
+    agent.bootLog.push('beforeStart');
   });
 
-  app.ready(()=> {
-    app.bootLog.push('ready');
+  agent.ready(()=> {
+    agent.bootLog.push('ready');
   });
 };
diff --git a/test/fixtures/boot/app/plugin/boot-plugin/app.js b/test/fixtures/boot/app/plugin/boot-plugin/app.js
index 5a25f77b..dc3e751c 100644
--- a/test/fixtures/boot/app/plugin/boot-plugin/app.js
+++ b/test/fixtures/boot/app/plugin/boot-plugin/app.js
@@ -2,7 +2,7 @@
 const sleep = require('mz-modules/sleep');
 
 module.exports = app => {
-  app.bootLog.push('app.js');
+  app.bootLog.push('app.js in plugin');
   app.beforeStart(async () => {
     await sleep(5);
     app.bootLog.push('beforeStart');
diff --git a/test/fixtures/boot/app/plugin/boot-plugin/package.json b/test/fixtures/boot/app/plugin/boot-plugin/package.json
index 4c5f4b61..f0b53535 100644
--- a/test/fixtures/boot/app/plugin/boot-plugin/package.json
+++ b/test/fixtures/boot/app/plugin/boot-plugin/package.json
@@ -1,6 +1,9 @@
 {
   "name": "bootPlugin",
   "eggPlugin": {
-    "name": "bootPlugin"
+    "name": "bootPlugin",
+    "dependencies": [
+      "bootPluginDep"
+    ]
   }
 }
diff --git a/test/fixtures/boot/config/plugin.js b/test/fixtures/boot/config/plugin.js
index 0f6cb614..5bfbd3b9 100644
--- a/test/fixtures/boot/config/plugin.js
+++ b/test/fixtures/boot/config/plugin.js
@@ -6,3 +6,7 @@ exports.bootPlugin = {
   enable: true,
   path: path.join(__dirname, '../app/plugin/boot-plugin'),
 };
+exports.bootPluginDep = {
+  enable: true,
+  path: path.join(__dirname, '../app/plugin/boot-plugin-dep'),
+};
diff --git a/test/fixtures/egg-ts/plugins/a/package.json b/test/fixtures/egg-ts/plugins/a/package.json
index 1aeaf2c8..1e45a636 100644
--- a/test/fixtures/egg-ts/plugins/a/package.json
+++ b/test/fixtures/egg-ts/plugins/a/package.json
@@ -1,3 +1,6 @@
 {
-  "name": "a"
-}
\ No newline at end of file
+  "name": "a",
+  "eggPlugin": {
+    "name": "a"
+  }
+}
diff --git a/test/fixtures/egg/index.js b/test/fixtures/egg/index.js
index bae255d5..81f6f435 100644
--- a/test/fixtures/egg/index.js
+++ b/test/fixtures/egg/index.js
@@ -23,7 +23,6 @@ class AppLoader extends EggLoader {
     this.loadContextExtend();
     this.loadRequestExtend();
     this.loadResponseExtend();
-    this.loadBootHook();
     this.loadCustomApp();
     this.loadMiddleware();
     this.loadService();