Problem when saving blend file

i have a blender game file, but when i save it normaly (ctrl+s) why the file ( .blend ) become a copy file. and format file become " .BLEND1". then i got a lot of file when i save it. please help :(! thankyou

Blender creates a backup file on saving. This means your current .blend gets renamed to .blend1 while the saved one is a .blend. This way you can recover data that might not be in your current version.

As far as I remember the default setting is two backup files (.blend1 and .blend2).

You can configure that in the user settings (file tab).