In 1999, as a junior at Kyung Hee University, Chong was selected as a member of the South Korea national baseball team for the 1999 Intercontinental Cup in Sydney.

In 2001, signed by the SK Wyverns, he had a mediocre rookie season, pitching only 16.2 innings in 18 games as a setup man with a 5.40 ERA and 20 strikeouts, allowing 19 hits and 10 earned runs.

In 2004, Chong appeared in 52 games with 69.1 innings pitched and posted a record of 2–3 with a 2.34 ERA, 2 saves and a career-best 16 holds, allowing 62 hits and 2 home runs.

He came back from injury in the second half of the season and posted a remarkable ERA of 0.37, racking up 3 saves and 6 holds and allowing only 1 earned run in 24.1 innings pitched.

In 2008, Chong was called up for the South Korea national baseball team and participated in the 2008 Summer Olympic Games held in Beijing, China.

In the gold medal game, closer Chong contributed to escaping the one-out bases-loaded jam by inducing a game-ending double play along with battery mate Jin Kab-Yong to edge Cuba 3-2.