Under his brother's rule, Kim Yong-ju held key posts including Politburo member in the Workers' Party of Korea (WPK) during the 1960s and early 1970s, but he fell out of favour in 1974 following a power struggle with Kim Jong Il.

From 1998 until his death in 2021, he held the ceremonial position of Honorary Vice President of the Presidium of the Supreme People's Assembly (SPA), North Korea's parliament.

[1] After graduating from the economics department at Moscow State University in 1945,[4] where he also took a deep interest in philosophy,[5] Kim Yong-ju joined the Workers' Party of Korea.

His rise through the party's echelons was rapid; from the 1950s to the 1960s he was chief cadre (1954), vice-director (1957) and finally director (1960) of the WPK Organization and Guidance Department.

[9][10] Kim Yong-ju was appointed Honorary Vice-President of the Presidium of the Supreme People's Assembly in 1998.