Cat urine is laden with scented chemicals called pheromones. These chemicals serve as a signal to others. Usually, a cat sprays to send various messages like calling a mate, protecting his territory or as a result of stress.
Though cat spraying is a natural and innocent action, it's a behavior that even the most loving cat owners want to get rid of if they can. Don't try to punish your cats if they spray, as they're just doing what cats do. The easiest and most tried-and-true method of getting a cat to stop spraying is to have him neutered. Most spraying is due to a desire to mate, and getting rid of the source of that desire should most likely get rid of the problem.
If you can't get your cat neutered, or neutering doesn't stop him from spraying, you should think about figuring out the source of the problem that's causing your cat to spray. If he doesn't get along with another cat in the environment, try separating them for a time. Cat spraying can also be due to a medical problem, and is something you should discuss with your veterinarian.
Unless you clean all areas that have been sprayed thoroughly with a strong antibacterial cleanser, your cat will be tempted to spray the same area again. Remember when you spray that you probably cannot smell cat pheromones, but your cat can, so clean well to totally get rid of the odor.
A cat behaviorist can help you get to the bottom of your problems with your cat by reviewing the steps you've already taken and what your living situation is like. There are many reasons why a cat will have behavior problems, including his home, his food, his health, or his lack of companionship. Your vet can also help you work this out.
Cat behavior is often baffling, but if you try to understand your cat's reasons for spraying or other harmful actions you might find that there is a logical explanation. Cats can't speak for themselves, so when they are upset about something they spray or claw or cry.