Does your cat urinate in the house outside of the litter box? This is one of the most common behavioral problems in cats.
There are several things you can do to resolve the problem. First, make sure that your cat's problem is a behavioral problem and not due to an underlying medical condition such as a urinary tract infection or bladder stones. Your vet can diagnose these diseases by performing some simple tests.
Once you determine that the problem is behavioral, you need to take a close look at your home, the number of litter boxes you have, where the litter boxes are located, the type of litter boxes and litter you use and how you care for the boxes.
Understanding proper litter box location and care can make the difference between whether or not your cat uses the box.