Далянь Шидэ
Cao Xuan originally started his football career with the Dalian Shide F.C. youth team, however in 2000 he would move to Zhejiang so he could join and play for the Zhejiang Lücheng youth team. With them he would graduate to the senior team and start his professional football career at the bottom the Chinese league system, however after several seasons with the club he would see finally promoted to the Chinese Super League after seeing Zhejiang Lücheng come second in the second tier. He would be a vital member of the team to help establish the club as mid-table regulars for several seasons until the 2009 Chinese Super League saw the club struggle within the league, this saw Chinese international Du Wei brought in the following season to strengthen the team's defense and Cao would be dropped as a squad regular. When Du Wei left, Cao would re-establish himself as a vital member of the team's defence.