The difference between British Longhair cats and Chinchillas lies in their breed and appearance. Chinchillas are a color of Persian cats and belong to Persian cats, while British Longhair cats are an atavism of the British Shorthair, so these two cats are different breed; purebred chinchillas all have flat faces, and have black eye lines, black nose lines, black lip lines, and black flesh pads, a round head, and blue or green eyes, while British long-haired cats do not have flat faces. , but has a normal face shape, a relatively long nose bridge, and is good at catching mice.