Why is it that when i had to take prednisone that the swelling in my legs go down, and look normal, despite comment prednisone cause swelling?

That depends...: Why were you prescribed prednisone? Not knowing anything about the illness for which the medicine was prescribed, or what the medical history of the person taking it is, no doctor could give you any kind of meaningful statement here. Prednisone is a very widely used drug for a number of medical conditions, most of them involving inflammation, but not all. Try asking again with more background.