Wonju TG Xers / Wonju DB Promy

After college, Kim joined the Wonju TG Xers. He was the first overall pick of the 2002 KBL rookie draft.^[5][1] Kim had one of the best rookie recording averages with 17.04 points, 8.72 rebounds, 2.24 assists, and 2.07 blocks in the season. In addition, he helped the team win the championship keeping the goal in the post-season of the 2002-2003 league. Kim averaged 18.85 points, 8.85 rebounds, and 2.43 shoot-blocks and won the Most Valuable Player of the league in the 2003–2004 season. However, the Xers failed to win the championship of 2003–2004, losing to Jeonju KCC Egis. In spite of the team's loss, The Xers won the championship in the 2004–2005 season, and Kim won the Most Valuable Player of the post-season for the first time.

The Xers was taken over by Dongbu Group, was reorganized to Wonju Dongbu Promy, later shortened to Wonju DB Promy due to the company's rebranding. Though the Promy took third place, they failed in the playoff, losing to Daegu Orions. The next year, Kim was injured and could not participate. Therefore, Promy ranked eighth in the league and did not qualify for the play-offs.

In the 2007–2008 season, his team won the championship by defeating Seoul Samsung Thunders. Kim won the KBL Most Valuable Player Award for the second time and led the league in blocks that season.

During the 2011–12 season, Kim was a key player in Dongbu's defensive prowess, which led to the team earning the nickname "Dongbu Mountain Fortress".^[6] Along with center Rod Benson (206 meters) and forward Yoon Ho-young (197 meters), the trio were dubbed the "Triple Posts of the Dongbu Mountain Fortress" by the press after shutting down some of the league's best offensive players.^[7] Kim went on to win the KBL Defensive Player of the Year award while Yoon was named regular season MVP and Benson won the Foreign Player of the Year award.

Kim announced that he would be retiring after the 2017-18 season. Although he was mostly the sixth man, he played a crucial role in Promy finishing at the top of the league. He was nominated for the Defensive Player of the Year and won the Sixth Man Award at the annual KBL awards.^[8]

Kim is the first player to exceed 1000 blocks in the KBL, earning him the nickname "Emperor of Blocks" (블록슛 황제).^[3][2] He was ranked second, behind Seo Jang-hoon, for the all-time most number of rebounds in KBL history; Seo's record was eventually surpassed by Ra Gun-ah in January 2022.^[9][10][11] He was the league's highest-paid domestic player from 2004 to 2012.^[12][13] In December 2018, Wonju DB Promy announced that his number 32 jersey would be permanently retired, the club's second jersey to be retired after his former teammate Hur Jae.^[14][15]

National team

Kim was first called up to the senior national team while in college. He won two gold medals at the Asian Games, the 2002 and 2014 editions.