diff --git a/app/models/archive_category.rb b/app/models/archive_category.rb
index 170468f..78e7abc 100644
--- a/app/models/archive_category.rb
+++ b/app/models/archive_category.rb
@@ -1,4 +1,5 @@
 class ArchiveCategory
   include Mongoid::Document
+  field :category_id, type: String
   field :sort_number, type: Integer
 end
\ No newline at end of file