At the age of 17, he was called up to China youth football team.
Duan Ju played for Tianjin football Team 2 from 1980 to 1983.
In 1988, Duan Ju played for China in the 1988 Asian Cup and football match at the 1988 Olympic Games.
In 1990, China lost to Thailand in football match at the 1990 Asian Games.
In 1993, Duan Ju retired in Japan and returned to China.