He defeated Iran's Mahmoud Miran for the gold medal in the open weight division at the 2006 Asian Games in Doha, Qatar.

[3] Kim made his official debut for the 2004 Summer Olympics in Athens, where he competed for the men's heavyweight class (+100 kg).

He defeated Spain's Aytami Ruano in the first preliminary round, before losing out his next match by a waza-ari-awasete-ippon (full point) and a soto makikomi (outer wraparound) to Italy's Paolo Bianchessi.

[4] Four years later, Kim qualified for the second time in the men's +100 kg class, as a 29-year-old, at the 2008 Summer Olympics in Beijing, after winning the bronze medal from the Asian Judo Championships in Jeju City.

[5] Unlike his previous Olympics, Kim defeated Haiti's Joel Brutus in the first preliminary round, before losing out his next match, by an ippon and a seoi nage, to Estonia's Martin Padar.