He was an active Hong Kong students' representative during the Tiananmen Square protests of 1989 and he once went to Beijing to join the hunger strike. In 1991, he was elected district board member. As at 2005, he is the youngest person ever to be elected to this post. He was a member of the Democratic Party (1994-2000) then joined the The Frontier (since 2000). He was in the same ticket with Albert Cheng in the Hong Kong legislative election, 2004, Cheng won a seat and To lost.