He has served as Member of the Kedah State Executive Council (EXCO) in Pakatan Rakyat (PR) administration under Menteri Besar Azizan Abdul Razak from March 2010 to 2013 as well as Member of the Kedah State Legislative Assembly (MLA) for Sidam from March 2008 to May 2013.
[5] In the 2008 Kedah state election, he defeated the candidate from Barisan Nasional, Fong Chok Gin with a majority of 3,618 votes.
[6] On 10 March 2010, he was appointed as Member of the Kedah State Executive Council (EXCO), replacing Tan Wei Shu who was dismissed by Menteri Besar Azizan Abdul Razak.
[8] On 14 March 2016, Tan Chow Kang announced his resignation from the People's Justice Party and established Sidam District Branch of the Parti Rakyat Malaysia to continue to fight for the concept of socialism.
[9][10][11] He contest in the 2018 Malaysian general election under the Parti Rakyat Malaysia (PRM) ticket for the Nibong Tebal parliamentary seat but lost with 55 votes and lost deposit.