The company asks people to submit funny or thought-provoking signature lines they have posted on instant messaging services like MSN and QQ, and on social networking services like Kaixin001.com, Renren.com and Sina Weibo.
By entering on the company's website, consumers are eligible to win coupons worth up to RMB5,000 (US$760).
The campaign is expected to boost sales in the coming months, as well as to promote its brand visibility among young people.
According to its website, C&A entered the Chinese market in 2007, with the opening of four stores in the country. Its major competitors are H&M, Zara and Gap.