Cats naturally prefer to eliminate in soft, sandy material, so most cats will use the litter box by choice. If your cat is going outside of his box, there is probably something about the box that he doesn t like. The most important thing to check for is a medical problem. If your kitty has a urinary or intestinal tract obstruction, he may associate the pain of trying to go the bathroom with the box itself. Or, he may not like the kitty litter you re using.
Some cats also object to scented litters.
Remember, though it may smell pleasant and fresh to you, his sensitive nose thinks it s a perfume explosion. Most cats are neat freaks, so cleaning the box out every day will help. Some particularly finicky cats may want you to clean it even more than that. Some cats also prefer to use separate boxes for urinating and defecating. Try setting out two boxes and see if that helps.