Can't help you with identifying the actor (whoever he is, he's cute!), but you could always try the Hong Kong Cinemagic website, which provides images of leading players for the movies in its own database - you may be able to identify him by going to the various films in which you know he's already appeared, and checking the galleries for each one. Here's the URL, hope it helps! :

http://www.hkcinemagic.com/en/imovie.asp?lid=4

Vincent Lam Wai.