diff --git a/app/views/attachments/_form.html.erb b/app/views/attachments/_form.html.erb
index d6cbb72fe..16de21226 100644
--- a/app/views/attachments/_form.html.erb
+++ b/app/views/attachments/_form.html.erb
@@ -3,7 +3,7 @@
   <% container.attachments.each_with_index do |attachment, i| %>
     <span id="attachments_p<%= i %>" class="attachment">
       <%= text_field_tag("attachments[p#{i}][filename]", attachment.filename, :class => 'filename readonly', :readonly=>'readonly')%>
-      <%= text_field_tag("attachments[p#{i}][description]", attachment.description, :maxlength => 255, :placeholder => l(:label_optional_description), :class => 'description', :style=>"display: inline-block;") %>
+      <%= text_field_tag("attachments[p#{i}][description]", attachment.description, :maxlength => 254, :placeholder => l(:label_optional_description), :class => 'description', :style=>"display: inline-block;") %>
       <span class="ispublic-label"><%= l(:field_is_public)%>:</span>
       <%= check_box_tag("attachments[p#{i}][is_public_checkbox]", attachment.is_public, :class => 'is_public')%>
       <%= if attachment.id.nil?
diff --git a/public/javascripts/attachments.js b/public/javascripts/attachments.js
index 1b60b370e..c20617ce5 100644
--- a/public/javascripts/attachments.js
+++ b/public/javascripts/attachments.js
@@ -22,7 +22,7 @@ function addFile(inputEl, file, eagerUpload) {
 
     fileSpan.append(
         $('<input>', { 'type': 'text', 'class': 'filename readonly', 'name': 'attachments[' + attachmentId + '][filename]', 'readonly': 'readonly'} ).val(file.name),
-        $('<input>', { 'type': 'text', 'class': 'description', 'name': 'attachments[' + attachmentId + '][description]', 'maxlength': 255, 'placeholder': $(inputEl).data('description-placeholder') } ).toggle(!eagerUpload),
+        $('<input>', { 'type': 'text', 'class': 'description', 'name': 'attachments[' + attachmentId + '][description]', 'maxlength': 254, 'placeholder': $(inputEl).data('description-placeholder') } ).toggle(!eagerUpload),
         $('<span >公开:</span>').attr({  'class': 'ispublic-label' }) ,
         $('<input>', { 'type': 'checkbox', 'class': 'is_public_checkbox','value':1, 'name': 'attachments[' + attachmentId + '][is_public]', checked:'checked' } ).toggle(!eagerUpload),
         $('<a>&nbsp</a>').attr({ 'href': "#", 'class': 'remove-upload', 'data-confirm' : "您确定要删除吗？" }).click(removeFile).toggle(!eagerUpload),