Upon graduation from Hanyang University in February 1979, he joined the POSCO baseball club in the Korean amateur league.

In September 1982, Jang competed in the 1982 Amateur World Series as a member of the South Korean national baseball team and helped his team to win its first world championship as a starting right fielder.

In a ten-season career, Jang batted .331 with 78 home runs and 437 RBI in 961 games and ended with a .430 on-base percentage.

Jang also topped the KBO in on-base percentage in six seasons and won five straight Golden Gloves from 1983 to 1987 for defensive excellence.

[2] Following his playing career, Jang coached for the Lotte Giants in 1994 and the Samsung Lions in 2000.