Sun Shoubo started his professional football career in 2001 when he played for Dalian Sidelong who were in the third tier of the Chinese league system.
With the chance to play in the top tier Sun Shoubo would transfer to Sichuan First City at the beginning of the 2004 Chinese Super League season.
[2] He would immediately establish himself as their first choice goalkeeper when he made his debut in the first game of the season on May 16, 2004, against Beijing Hyundai in a 1–1 draw.
[3] While he was an integral part of the team that finished ninth within the league Sun Shoubo would only stay with Sichuan Guancheng for one season after Dalian Shide showed an interest in him.
He would not have to wait long before he made his debut coming on as a substitute for an injured Chen Dong on April 17, 2005, in a game against Shanghai Zobon, which Dalian won 1–0.