We knew about the Chengdu J-20—China's fifth generation stealth fighter. As it turns out, it's not the only one. According to China Defense Blog, this is the J-21/J31. It looks even more like the F-22 Raptor than the Chengdu.
China Defense Blog says that this new plane is being developed by tChina's 601 Aircraft Design Institute/Shenyang Aircraft Corporation. It appears to be the very first flying prototype, serial 001.