Career
He competed in the 2006 Winter Olympics with partner Phyo Yong-myong, with whom he teamed up in the fall of 2005. They withdrew after the short program However, Sung was not age-eligible for the Olympics, so he switched partners for the Olympics and returned to partnering with Sung after the Olympics.
Jong has also competed with Jang Kyong-ok and Paek Mi-hyang.