Jackie Chan is a marvelous martial artist. He took all around martial arts as a child, never really focusing on one or the other. But then after he had entered into acting, he got a chance to study Hapkido under the great Jin Pal Kim, a grand master who Chin highly looked up to. He attained his black belt and fell in love with the discipline of Hapkido.
Jackie is also trainined in a number of other martial art forms like Jeet Kune Do, Taekwondo, Karate, and even Judo. Since he was a young child, he has been extraordinary at both martial arts and at gymnastics.
He is limber and is also very focused in his training so he made a good pupil when he was younger and an even better one when he was an adult, in martial arts, that is. He was never a good achedemic student but with the talent he has elsewhere, it really didn't end up mattering. He did well despite the odds.