Jang, who won the men's individual pursuit, and Park, bronze medallist in the men's road race, had already joined forces to win gold as part of the four-man pursuit team, but have now added the coveted Madison prize.
The duo won the 200 lap (50km) race - which has 10 intermediate sprints every 20 laps - with 35 points,14 ahead of Kazakhstan's Iliya Chernyshov and Alexey Lyalko, who scored 21 to take silver.
IR Iran's Medhi Sohabi and Amir Zargari, both silver medallists in the men's team pursuit, claimed bronze with 17 points.
15th Asian Games, Doha 2006