diff --git a/apps/pc_backend/i18n/messages.ja.xml b/apps/pc_backend/i18n/messages.ja.xml
index b33cf4f..f22b176 100644
--- a/apps/pc_backend/i18n/messages.ja.xml
+++ b/apps/pc_backend/i18n/messages.ja.xml
@@ -78,6 +78,14 @@
         <source>Please input the number of limit that reflects to the diary comment api.</source>
         <target>日記コメントAPIの取得件数を入力してください。</target>
       </trans-unit>
+      <trans-unit id="">
+        <source>Diary comment reply</source>
+        <target>日記コメント返信機能設定</target>
+      </trans-unit>
+      <trans-unit id="">
+        <source>If this is used, you can reply to the diary comment.</source>
+        <target>使用するに設定した場合、クリックした日記コメントに返信することができます。</target>
+      </trans-unit>
     </body>
   </file>
 </xliff>
diff --git a/apps/pc_frontend/modules/diaryComment/templates/_list.php b/apps/pc_frontend/modules/diaryComment/templates/_list.php
index dc648ca..7fb7921 100644
--- a/apps/pc_frontend/modules/diaryComment/templates/_list.php
+++ b/apps/pc_frontend/modules/diaryComment/templates/_list.php
@@ -1,3 +1,13 @@
+<script type="text/javascript">
+$(document).ready(function() {
+  $('.reply').click(function() {
+    var element = $('#diary_comment_body'); 
+    element.val(element.val() + '>>' + $(this).attr('number') + ' ' + $(this).attr('name') + "\n");
+    element.focus();
+  })
+})
+</script>
+
 <?php use_helper('opDiary') ?>
 
 <?php if ($pager->getNbResults()): ?>
@@ -40,6 +50,9 @@
 <?php if ($diary->member_id === $sf_user->getMemberId() || $comment->member_id === $sf_user->getMemberId()): ?>
  <?php echo link_to(__('Delete'), 'diary_comment_delete_confirm', $comment) ?>
 <?php endif; ?>
+<?php if('1'== Doctrine::getTable('SnsConfig')->get('op_diary_plugin_diary_comment_reply')): ?>
+  <a class="reply" href="javascript:void(0);" name="<?php echo $comment->Member->name; ?>" number="<?php echo $comment->number; ?>"><?php echo __('Reply') ?></a>
+<?php endif; ?>
 </p>
 </div>
 <div class="body">
diff --git a/i18n/messages.ja.xml b/i18n/messages.ja.xml
index 859a78a..b46a470 100644
--- a/i18n/messages.ja.xml
+++ b/i18n/messages.ja.xml
@@ -310,6 +310,10 @@
         <source>over %years% years ago</source>
         <target>%years%年以上前</target>
       </trans-unit>
+      <trans-unit id="">
+        <source>Reply</source>
+        <target>返信する</target>
+      </trans-unit>
     </body>
   </file>
 </xliff>
diff --git a/lib/form/opDiaryPluginConfigurationForm.class.php b/lib/form/opDiaryPluginConfigurationForm.class.php
index ce938b3..ae89c77 100644
--- a/lib/form/opDiaryPluginConfigurationForm.class.php
+++ b/lib/form/opDiaryPluginConfigurationForm.class.php
@@ -61,12 +61,17 @@ public function configure()
     $this->setDefault('diary_comment_api_limit', Doctrine::getTable('SnsConfig')->get('op_diary_plugin_diary_comment_api_limit', '15'));
     $this->widgetSchema->setHelp('diary_comment_api_limit', 'Please input the number of limit that reflects to the diary comment api.');
 
+    $this->setWidget('diary_comment_reply', new sfWidgetFormSelectRadio(array('choices' => $choices)));
+    $this->setValidator('diary_comment_reply', new sfValidatorChoice(array('choices' => array_keys($choices))));
+    $this->setDefault('diary_comment_reply', Doctrine::getTable('SnsConfig')->get('op_diary_plugin_diary_comment_reply', '0'));
+    $this->widgetSchema->setHelp('diary_comment_reply', 'If this is used, you can reply to the diary comment.');
+    
     $this->widgetSchema->setNameFormat('op_diary_plugin[%s]');
   }
 
   public function save()
   {
-    $names = array('use_open_diary', 'use_email_post', 'update_activity', 'search_enable', 'search_period_enable', 'search_period', 'diary_api_limit', 'diary_comment_api_limit');
+    $names = array('use_open_diary', 'use_email_post', 'update_activity', 'search_enable', 'search_period_enable', 'search_period', 'diary_api_limit', 'diary_comment_api_limit', 'diary_comment_reply');
 
     foreach ($names as $name)
     {
diff --git a/web/css/diary.css b/web/css/diary.css
index 4e983f2..d7abd41 100644
--- a/web/css/diary.css
+++ b/web/css/diary.css
@@ -119,3 +119,7 @@
 #diarySearchFormLine p.form {
   text-align: right;
 }
+
+.title .heading .reply {
+  float: right;
+}