diff --git a/app/controllers/blogs_controller.rb b/app/controllers/blogs_controller.rb
index 6be17f1d3..07bf60464 100644
--- a/app/controllers/blogs_controller.rb
+++ b/app/controllers/blogs_controller.rb
@@ -28,7 +28,11 @@ class BlogsController < ApplicationController
   end
   private
   def find_blog
-    @blog = Blog.find(params[:blog_id])
+    if params[:blog_id]
+      @blog = Blog.find(params[:blog_id])
+    else
+      render_404
+    end
     if @blog.nil?
       #如果某个user的blog不存在，那么就创建一条
       @blog = Blog.create(:name=>User.find(params[:id]).realname ,
diff --git a/public/javascripts/blog.js b/public/javascripts/blog.js
index 62dbaedc5..feaab0100 100644
--- a/public/javascripts/blog.js
+++ b/public/javascripts/blog.js
@@ -40,8 +40,8 @@ function regexTopicDescription()
         $("#message_content_span").css('color','#ff0000');
         return false;
     }
-    else if(name.length >=6000){
-        $("#message_content_span").text("描述最多3000个汉字(或6000个英文字符)");
+    else if(name.length >=20000){
+        $("#message_content_span").text("描述最多20000个汉字(或40000个英文字符)");
         $("#message_content_span").css('color','#ff0000');
         return false;
     }