My cat is constantly scratching himself to the place that he has sores on his head -it is not fleas

There is a difference in whether your cat is creating the sores from itching skin or if the sores came from a fight and he's just scratching the wound. If the latter is the case, put some anti-bacterial cream on it and get one of the small plastic collars to keep him from scratching until it heals.

If he is creating the wounds from itchy skin, I'd consider changing his food. Cats are meat eaters and some cat foods have a lot of grains that create alergy symptoms. EVO dog and cat food works well for dealing with that problem.

http://www.evopet.com/products/default.asp?id=1500