diff --git a/app/views/layouts/_logined_header.html.erb b/app/views/layouts/_logined_header.html.erb
index 00dbba16..57c816bf 100644
--- a/app/views/layouts/_logined_header.html.erb
+++ b/app/views/layouts/_logined_header.html.erb
@@ -19,6 +19,7 @@
         </li>
       <% end %>
       <li class="<%= params[:controller] == "competitions" ? " active" : "" %>"><%= link_to "在线竞赛", competitions_path %></li>
+      <li class="<%= params[:controller] == "libraries" ? " active" : "" %>"><%= link_to "教学案例", libraries_path %></li>
       <li class="<%= params[:controller] == "forums" ? " active" : "" %>"><%= link_to "交流问答", forums_path %></li>
       <% if User.current.ec_school.present? %>
         <li class="<%= ecs_controller.include?(params[:controller]) ? " active" : "" %>" id="ec_banner">
diff --git a/app/views/layouts/_unlogin_header.html.erb b/app/views/layouts/_unlogin_header.html.erb
index 3dcf2ca8..1e5ed6f5 100644
--- a/app/views/layouts/_unlogin_header.html.erb
+++ b/app/views/layouts/_unlogin_header.html.erb
@@ -20,6 +20,7 @@
         </li>
       <% end %>
       <li class="<%= params[:controller] == "competitions" ? " active" : "" %>"><%= link_to "在线竞赛", competitions_path %></li>
+      <li class="<%= params[:controller] == "libraries" ? " active" : "" %>"><%= link_to "教学案例", libraries_path %></li>
       <li class="<%= params[:controller] == "forums" ? " active" : "" %>"><%= link_to "交流问答", forums_path %></li>
       <!--<li><%#= link_to "活动竞赛", competitions_path %></li>-->
     </ul>
diff --git a/app/views/libraries/index.html.erb b/app/views/libraries/index.html.erb
index 8e52e85b..f81494e9 100644
--- a/app/views/libraries/index.html.erb
+++ b/app/views/libraries/index.html.erb
@@ -1,4 +1,4 @@
-<img src="/images/educoder/teach_ex.png" width="100%"/>
+<img src="/images/educoder/teach_ex.jpg" width="100%"/>
 <div class="educontent">
   <div class="edu-back-white mb30 mt30">
     <p class="padding20-30 clearfix bor-bottom-greyE">
diff --git a/public/images/educoder/teach_ex.jpg b/public/images/educoder/teach_ex.jpg
new file mode 100644
index 00000000..eb117017
Binary files /dev/null and b/public/images/educoder/teach_ex.jpg differ
diff --git a/public/images/educoder/teach_ex.png b/public/images/educoder/teach_ex.png
deleted file mode 100644
index 458f21be..00000000
Binary files a/public/images/educoder/teach_ex.png and /dev/null differ