diff --git a/app/Http/Controllers/RepliesController.php b/app/Http/Controllers/RepliesController.php
new file mode 100644
index 0000000..70f0321
--- /dev/null
+++ b/app/Http/Controllers/RepliesController.php
@@ -0,0 +1,62 @@
+<?php
+
+namespace App\Http\Controllers;
+
+use App\Http\Requests\ReplyRequest;
+use App\Models\Reply;
+
+class RepliesController extends Controller
+{
+    public function __construct()
+    {
+        $this->middleware('auth', ['except' => ['index', 'show']]);
+    }
+
+    public function index()
+    {
+        $replies = Reply::paginate();
+        return view('replies.index', compact('replies'));
+    }
+
+    public function show(Reply $reply)
+    {
+        return view('replies.show', compact('reply'));
+    }
+
+    public function create(Reply $reply)
+    {
+        return view('replies.create_and_edit', compact('reply'));
+    }
+
+    public function store(ReplyRequest $request)
+    {
+        $reply = new Reply();
+        $reply->setAttribute('topic_id', $request->get('topic_id'));
+        $reply->setAttribute('user_id', \Auth::id());
+        $reply->setAttribute('content', $request->get('content'));
+        $reply->save();
+        return redirect()->back()->with('success', '回复成功.');
+    }
+
+    public function edit(Reply $reply)
+    {
+        $this->authorize('update', $reply);
+        return view('replies.create_and_edit', compact('reply'));
+    }
+
+    public function update(ReplyRequest $request, Reply $reply)
+    {
+        $this->authorize('update', $reply);
+        $reply->update($request->all());
+
+        return redirect()->route('replies.show', $reply->id)->with('message', 'Updated successfully.');
+    }
+
+    public function destroy(Reply $reply)
+    {
+        $this->authorize('destroy', $reply);
+        $reply->delete();
+
+        return redirect()->back()->with('success', '删除成功.');
+    }
+}
\ No newline at end of file
diff --git a/app/Http/Requests/ReplyRequest.php b/app/Http/Requests/ReplyRequest.php
new file mode 100644
index 0000000..cd62bed
--- /dev/null
+++ b/app/Http/Requests/ReplyRequest.php
@@ -0,0 +1,50 @@
+<?php
+
+namespace App\Http\Requests;
+
+class ReplyRequest extends Request
+{
+    public function rules()
+    {
+        switch ($this->method()) {
+            // CREATE
+            case 'POST':
+                {
+                    return [
+                        'content' => 'required|max:255',
+                        'topic_id' => 'required|integer'
+                    ];
+                }
+            // UPDATE
+            case 'PUT':
+            case 'PATCH':
+                {
+                    return [
+                        // UPDATE ROLES
+                    ];
+                }
+            case 'GET':
+            case 'DELETE':
+            default:
+                {
+                    return [];
+                };
+        }
+    }
+
+    public function messages()
+    {
+        return [
+            // Validation messages
+        ];
+    }
+
+
+    public function attributes()
+    {
+        return [
+            'content' => '回复内容',
+            'topic_id' => '回复的主题'
+        ];
+    }
+}
diff --git a/app/Observers/ReplyObserver.php b/app/Observers/ReplyObserver.php
index c646a8e..aee8d0b 100644
--- a/app/Observers/ReplyObserver.php
+++ b/app/Observers/ReplyObserver.php
@@ -11,11 +11,16 @@ class ReplyObserver
 {
     public function creating(Reply $reply)
     {
-        //
+        $reply->setAttribute('content', clean($reply->getAttribute('content'), 'user_topic_body'));
     }
 
     public function updating(Reply $reply)
     {
         //
     }
+
+    public function created(Reply $reply)
+    {
+        $reply->topic->increment('reply_count', 1);
+    }
 }
\ No newline at end of file
diff --git a/app/Providers/AppServiceProvider.php b/app/Providers/AppServiceProvider.php
index 3d89c32..3520af8 100644
--- a/app/Providers/AppServiceProvider.php
+++ b/app/Providers/AppServiceProvider.php
@@ -2,7 +2,9 @@
 
 namespace App\Providers;
 
+use App\Models\Reply;
 use App\Models\Topic;
+use App\Observers\ReplyObserver;
 use App\Observers\TopicObserver;
 use Carbon\Carbon;
 use Illuminate\Support\ServiceProvider;
@@ -18,6 +20,7 @@ class AppServiceProvider extends ServiceProvider
     {
         Carbon::setLocale('zh');
         Topic::observe(new TopicObserver());
+        Reply::observe(new ReplyObserver());
 
     }
 
diff --git a/resources/views/topics/_reply_box.blade.php b/resources/views/topics/_reply_box.blade.php
index e69de29..1aec88d 100644
--- a/resources/views/topics/_reply_box.blade.php
+++ b/resources/views/topics/_reply_box.blade.php
@@ -0,0 +1,12 @@
+@include('common.error')
+<div class="reply-box">
+    <form action="{{ route('replies.store') }}" method="POST" accept-charset="UTF-8">
+        <input type="hidden" name="_token" value="{{ csrf_token() }}">
+        <input type="hidden" name="topic_id" value="{{ $topic->id }}">
+        <div class="form-group">
+            <textarea class="form-control" rows="3" placeholder="分享你的想法" name="content"></textarea>
+        </div>
+        <button type="submit" class="btn btn-primary btn-sm"><i class="fa fa-share"></i>回复</button>
+    </form>
+</div>
+<hr>
\ No newline at end of file
diff --git a/resources/views/topics/show.blade.php b/resources/views/topics/show.blade.php
index 2714a57..c3b38e1 100644
--- a/resources/views/topics/show.blade.php
+++ b/resources/views/topics/show.blade.php
@@ -67,7 +67,7 @@
             {{-- 用户回复列表 --}}
             <div class="panel panel-default topic-reply">
                 <div class="panel-body">
-                    @include('topics._reply_box', ['topic' => $topic])
+                    @includeWhen(Auth::check(),'topics._reply_box', ['topic' => $topic])
                     @include('topics._reply_list', ['replies' => $topic->replies()->with('user')->get()])
                 </div>
             </div>
diff --git a/routes/web.php b/routes/web.php
index f43c968..42b9b53 100644
--- a/routes/web.php
+++ b/routes/web.php
@@ -38,4 +38,4 @@ Route::resource('categories', 'CategoriesController', ['only' => ['show']]);
 Route::post('upload_image', 'TopicsController@uploadImage')->name('topics.upload_image');
 
 
-Route::resource('replies', 'RepliesController', ['only' => ['index', 'show', 'create', 'store', 'update', 'edit', 'destroy']]);
\ No newline at end of file
+Route::resource('replies', 'RepliesController', ['only' => ['store', 'destroy']]);
\ No newline at end of file