 
| Roles | Competed in Olympic Games | 
|---|---|
| Sex | Male | 
| Full name | Jang•Jae-Seong | 
| Used name | Jang•Jae-Seong | 
| Name order | Oriental | 
| Original name | 장•재성 | 
| Other names | Jang Jae-Sung | 
| Born | 15 March 1975 | 
| Measurements | 173 cm / 63 kg | 
| Affiliations | Korea National Housing Corporation, Seoul | 
| NOC |  Republic of Korea | 
| Medals | OG | 
| Gold | 0 | 
| Silver | 1 | 
| Bronze | 1 | 
| Total | 2 | 
Jang Jae-Sung had the following finishes at major championships – 1999 World Championship: 63.0 kg. Freestyle (2nd); 2001 World Championship: 69.0 kg. Freestyle (3rd); 1998 World Championship: 63.0 kg. Freestyle (5th); 2003 World Championship: 74.0 kg. Freestyle (24th); 1996 Asian Championship: 62.0 kg. Freestyle (2nd); 1998 Asian Games: 63.0 kg. Freestyle (1st); 1994 Asian Games: 62.0 kg. Freestyle (2nd).
| Games | Discipline (Sport) / Event | NOC / Team | Pos | Medal | As | |
|---|---|---|---|---|---|---|
| 1996 Summer Olympics | Wrestling |  KOR | Jang Jae-Seong | |||
| Featherweight, Freestyle, Men (Olympic) | 2 | Silver | ||||
| 2000 Summer Olympics | Wrestling |  KOR | Jang Jae-Seong | |||
| Lightweight, Freestyle, Men (Olympic) | 3 | Bronze |