Kim Yu-jong studied in Switzerland with Kim Jong-un from 1996 to 2000 and later graduated from Kim Il Sung University in Pyongyang, which is related to her elder brother since childhood.
At the age of 20, Kim Yu-jong quickly stepped on the ladder of government and began appearing alongside Kim Jong-un since December 2011, when she attended the funeral ceremony for her father.
In 2012, Kim Yuzhong assumed the position of Director of the Protocol Section of the National Defense Committee of her country.
In March 2014, North Korean television reported for the first time that it was a "high official" in the Central Committee of the ruling Labor Party, when it appeared alongside Kim Jong-un during the elections of the Supreme People's Assembly.
She has been promoted to First Vice-Chairman of the Central Committee of the ruling party and since July 2015 has been the director of propaganda department of the Korean Workers' Party.
In 2017, the US Treasury Department put its name on the sanctions list, accusing it of involvement in human rights violations in North Korea.
She married in 2015 from the son of a senior state official, Choi Young-Hai, the second man on the National Defense Committee, and had a child.