Cao Yunding started his football career when he joined the
Genbao Football Academy in 2000 and was promoted to
Shanghai East Asia's first team during the 2006 season. He scored his first goal for the club on 20 August 2006 in a 4-1 win against
Wuhan Yaqi. Cao established himself as a regular in the team as the club won third tier title and promotion to the second tier during the 2007 season. In the 2009 season, the club became genuine promotion candidates and Cao played twenty-two games and scored two goals as Shanghai East Asia finished fourth and narrowly missed out on promotion. Cao made another twenty appearances and scored two goals during the 2010 season as he helped guide the club to another fourth-place finish. On 12 February 2011, Cao transferred to
Chinese Super League side
Shanghai Shenhua. He made his debut for the club on 2 March 2011 in a 0-0 draw against
Kashima Antlers in the
2011 AFC Champions League. He scored his first goal for the club on 21 September 2011 in a 1-0 win against
Yanbian Baekdu Tigers in the
2011 Chinese FA Cup. He then scored his first league goal for the club on 24 September 2011 in a 3-2 loss against
Jiangsu Sainty. He extended his contract with the club for five more years on 19 November 2017. On 31 December 2024, Cao announced his retirement from professional football through the social media. ==International career==