JAMES COLLINSNow, let's see. How many short, overweight, non-English-speaking Chinese boyhood friends of Jackie Chan have ever become stars on U.S. television? While no definitive answer is possible, of course, an exhaustive study of the available data suggests that the number is zero. With the arrival of Samo Hung, however, the figure is about to change. Hung grew up in Hong Kong with Chan and worked with him in 23 movies. Now the actor-turned-director has turned actor again, starring in Martial Law, a new drama that lights up Saturday evenings on the CBS network. Despite the lack of precedent, the series has won good ratings, and Hung has shown himself to be as appealing as any of American TV's leading men.Martial Law concerns Samo Law, a detective from Shanghai played by Hung, who has been assigned to the Los Angeles police department. In many ways it's an old-fashioned cop show, with crude plots and characterizations--but this actually makes it a pleasure to watch, since it provides a B-movie charge and doesn't require the viewer to care about anyone's alcoholism or love life. What makes Martial Law distinct, though, are its intricate, speed-of-light action sequences and its humor. These both derive from the talents of Hung, who has been a star of comedy-action films in Hong Kong since the 1970s. The result is a series that will win no Emmy awards but is highly entertaining, and whose sheer craft, at least in its choreography and acrobatics, puts most American TV to shame.A year ago, Hung would never have imagined that he would be appearing in prime time. Last March Terry Botwick, a programming executive at CBS, learned that veteran Hong Kong action director Stanley Tong (Supercop) was interested in developing a martial-arts show for television. That's something Botwick had wanted to do for a long time, and he and Tong proposed such a series to Leslie Moonves, the head of CBS Television. Moonves liked the idea. He ordered up a pilot, collapsing the development process, which usually takes months, into seven weeks.The first choice for the lead was Jackie Chan himself, but he preferred to keep making films like Rush Hour. So Tong and his partners suggested Hung, who, as another huge Hong Kong star, was a logical substitute. Hung took the part because he liked the character, who is tough, street-smart and wise. In movies and television shows, there has never been a really good Chinese lead, Hung says. So often, the Chinese look like they are very scared and shy. I said I would try a new kind of character.PAGE 1 | Action idol Jackie Chan finally makes it big in Tinseltown with his new box-office smash, Rush Hour I'm crazy, but I won't risk my life Which of Jackie Chan's previous movies is your favorite? Which action hero do you think would win an on-screen battle: Jackie Chan or Jet Li?Hung, 46, who has starred in or directed more than 140 films, met Chan as a child when they attended the China Drama Academy in Hong Kong. There they learned acting, tumbling and martial arts. Hung was older and would bully Chan. Even now, according to Chan, Hung treats him overbearingly. He is like a Hitler, Chan says. That sentiment notwithstanding, the two are good friends. We are very close, says Hung jokingly. I used to beat him up every day.Last year, Hung and his wife Mina, a former Miss Hong Kong, moved to Los Angeles, where Hung hoped to direct. He didn't intend to do any acting until Tong, with whom he had worked often, proposed Martial Law. Now Hung spends 12-hour days on the set, with the occasional game of golf as his only distraction. The show has two crews working at once, one shooting the dramatic sequences and the other shooting the action. The latter crew consists of Tong and several other veterans of the Hong Kong film industry. Hung helps stage the fights, performs all his stunts and appears in the dramatic scenes. Still, he says, the biggest challenge for me is English. Before the show went into production, he took an eight-hour-a-day Berlitz course for about three months.Martial Law would never work if audiences didn't like and root for the main character. Of course, Hung's convex silhouette gives him personal appeal and makes his twirls and vaults all the more impressive. But he is also a fine actor, quietly funny and a little bit vulnerable. We had to find somebody who is good in action and also has a heart, says Tong. They found him in Hung, America's least likely, most refreshing network star. | 2 Action idol Jackie Chan finally makes it big in Tinseltown with his new box-office smash, Rush Hour I'm crazy, but I won't risk my life Which of Jackie Chan's previous movies is your favorite? Which action hero do you think would win an on-screen battle: Jackie Chan or Jet Li?