diff --git a/db/migrate/20150708025533_add_proportion_to_programing.rb b/db/migrate/20150708025533_add_proportion_to_programing.rb
new file mode 100644
index 000000000..b3da59c25
--- /dev/null
+++ b/db/migrate/20150708025533_add_proportion_to_programing.rb
@@ -0,0 +1,9 @@
+class AddProportionToPrograming < ActiveRecord::Migration
+  def up
+    add_column :homework_detail_programings, :ta_proportion, :float, :default => 0.1
+  end
+
+  def down
+    remove_column :homework_detail_programings, :ta_proportion
+  end
+end