Des files contain information that at which position the small image is located in the sprite file or atlas image.Now I want to create .des file from a .png file can anyone tell me how to make .des files from .png files?

Off-topic, but please don't double post And welcome to the forums

I haven't a clue what a .des file is (neither does google). If you just want to store metadata about an image file there are a number of sprite sheet apps out there. Here's one:

http://zwopple.com/zwoptex/