After sitting out the first half of the 2006 season as required under the Korea Baseball Association rules for transfer students, Kim subsequently became the top right-handed starting pitcher at the high school level, hurling a four-hit complete game shutout with 13 strikeouts on June 30, 2006, in the first round of the Golden Lion Flag National Championship.
Kim became the first Korean high school pitcher ever to pitch a 10-inning no-hitter on July 14, 2007, in the second round of the Daebung Flag National Championship.
He collected his first pro league save on April 3, 2008, against the Hanwha Eagles, throwing one shutout inning.
After the 2010 season, Kim was selected for the South Korea national baseball team to compete in the Intercontinental Cup held in Taichung.
On March 6, 2012, he was banned from any professional baseball activities and was released by LG with former pitcher Park Hyun-june.