Jang Su Won (born July 16, 1980) is a former vocalist from the group Sechs Kies and a duet singer along with former Sechs Kies member Kim Jae Duc under Kiss Entertainment. He was known to be the most considerate of the group and also the youngest of member of the group. He was a sophomore is college as he was a member of the boy band. Though he had little parts in the group, his parts were very valuable as he sang it with much ease.