diff --git a/app/assets/stylesheets/posts.scss b/app/assets/stylesheets/posts.scss
index ed37598..8c425f7 100644
--- a/app/assets/stylesheets/posts.scss
+++ b/app/assets/stylesheets/posts.scss
@@ -77,18 +77,18 @@
   ol {
     @extend %post-list-common;
   }
-}
 
-.author {
-  border-top: 1px solid $border-gray;
-  padding: 1.5rem 0;
-  text-align: right;
-}
+  .author {
+    border-top: 1px solid $border-gray;
+    padding: 1.5rem 0;
+    text-align: right;
+  }
 
-.author__nickname {
-  font-size: .9rem
-}
+  .author__nickname {
+    font-size: .9rem
+  }
 
-.author__created-at {
-  font-size: .8rem
+  .author__created-at {
+    font-size: .8rem
+  }
 }
diff --git a/app/controllers/comments_controller.rb b/app/controllers/comments_controller.rb
new file mode 100644
index 0000000..1a46c4b
--- /dev/null
+++ b/app/controllers/comments_controller.rb
@@ -0,0 +1,22 @@
+class CommentsController < ApplicationController
+  def index
+    @comments = Comment.all
+  end
+
+  def create
+    post = Post.find(params[:post_id])
+    @comment = post.comments.build(comment_params)
+
+    if @comment.save
+      redirect_to post, notice: "Comment has been successfully created."
+    else
+      redirect_to post, alert: "Hoge!"
+    end
+  end
+
+  private
+
+    def comment_params
+      params.require(:comment).permit(:body).merge(commented_by: current_user)
+    end
+end
diff --git a/app/controllers/posts_controller.rb b/app/controllers/posts_controller.rb
index ed0eeb5..3aae6ba 100644
--- a/app/controllers/posts_controller.rb
+++ b/app/controllers/posts_controller.rb
@@ -6,6 +6,8 @@ def index
   end
 
   def show
+    @comment = @post.comments.new
+    @comments = @post.comments
   end
 
   def new
diff --git a/app/models/comment.rb b/app/models/comment.rb
new file mode 100644
index 0000000..fba6813
--- /dev/null
+++ b/app/models/comment.rb
@@ -0,0 +1,4 @@
+class Comment < ApplicationRecord
+  belongs_to :post
+  belongs_to :commented_by, class_name: "User"
+end
diff --git a/app/models/post.rb b/app/models/post.rb
index 960cb9c..fb2f04a 100644
--- a/app/models/post.rb
+++ b/app/models/post.rb
@@ -1,5 +1,6 @@
 class Post < ApplicationRecord
   belongs_to :created_by, class_name: "User"
+  has_many :comments, dependent: :destroy
 
   validates :title, presence: true
 
diff --git a/app/models/user.rb b/app/models/user.rb
index 7aa2fe7..923d793 100644
--- a/app/models/user.rb
+++ b/app/models/user.rb
@@ -2,6 +2,7 @@ class User < ActiveRecord::Base
   include Authenticator
 
   has_many :posts, foreign_key: "created_by_id"
+  has_many :comments, foreign_key: "commented_by_id"
 
   class << self
     def find_or_create_from(auth)
diff --git a/app/views/posts/show.html.slim b/app/views/posts/show.html.slim
index ef118c5..5581e6e 100644
--- a/app/views/posts/show.html.slim
+++ b/app/views/posts/show.html.slim
@@ -14,6 +14,21 @@
                 |  #{@post.created_by.nickname}
             .author__created-at.grey-text.text-darken-1
               = @post.created_at
+
+  = form_for @comment, url: post_comments_path(@post) do |f|
+    = f.text_field :body
+    = f.submit
+
+  - @comments.each do |comment|
+    .comment
+      .author
+        .author__nickname
+          = comment.commented_by.nickname
+        .author__created-at
+          = comment.created_at
+      .comment__body
+        == sanitize(auto_link(markdown_to_html(emojify(comment.body))))
+
 .row
   .col.s12
     = link_to edit_post_path(@post), class: 'waves-effect waves-light btn' do
diff --git a/config/routes.rb b/config/routes.rb
index 0eaae9a..9773f6f 100644
--- a/config/routes.rb
+++ b/config/routes.rb
@@ -1,7 +1,9 @@
 Rails.application.routes.draw do
   root to: "posts#index"
   resources :users, only: %i(index show)
-  resources :posts
+  resources :posts do
+    resources :comments, only: %i(index new create)
+  end
 
   get "login", to: "sessions#new"
   get "auth/:provider/callback", to: "sessions#create"
diff --git a/test/features/comment_creation_test.rb b/test/features/comment_creation_test.rb
new file mode 100644
index 0000000..b69844d
--- /dev/null
+++ b/test/features/comment_creation_test.rb
@@ -0,0 +1,18 @@
+require "test_helper"
+
+feature "CommentCreation" do
+  scenario "User create comment to post" do
+    stub_authentication_with "alice"
+
+    visit post_path(post)
+
+    body = "Lorem ipsum dolor sit amet"
+
+    fill_in "comment_body", with: body
+    click_button "create comment"
+
+    within ".comment__body" do
+      expect(page).must_have_content "Lorem ipsum dolor sit amet"
+    end
+  end
+end