Communist Party of Korea
After the end of World War II, in September 1945 he joined Pak's reconstructed Communist Party of Korea, serving as Pak's right hand as head of the publicity department while also working as a cadre of the Communist Party of South Korea. Kang's son-in-law Lee Sung-jin adopted the alias “Kim Tal-sam", previously used by Kang, when he led the Jeju Uprising in 1948.