A member of the Democratic Progressive Party, he served in the Legislative Yuan from 1996 to 2012 as a representative of Tainan.

[2] Affiliated with the Democratic Progressive Party's Welfare State Alliance,[3] he has also served as the DPP caucus whip.

In 2009, Lee was named the Democratic Progressive Party candidate for the Tainan County magistracy.

[2] Subsequently, Lee declared his candidacy for the mayoralty of Tainan, and he was challenged by Yeh Yi-jin, Su Huan-chih, and Hsu Tain-tsair.

[8][9] Su Tseng-chang named Lee one of three deputy secretaries-general of the Democratic Progressive Party in 2012.