Markis Kido
A men's doubles specialist, Guo has played on the world circuit since 2005, mainly in partnership with Xie Zhongbo. They have won the 2004 Polish Open, the 2005 China Masters and the 2008 India Open titles together, and Guo won the Austrian International title in 2007 with He Hanbin. Guo and Xie were quarterfinalists at the 2007 BWF World Championships. At the 2008 Olympics in Beijing they lost a tight round of 16 duel to the eventual gold medalists, Markis Kido and Hendra Setiawan of Indonesia. Guo is a member of China's world champion Thomas Cup (men's international) team.