After the Gulf war, ,China realized the importance of stealth aircraft. Then China devoted its energies to studyissng ways to ward off stealth aircraft. China not only bought the Su-27 in the 1990s, but also developed the J-11 based on the Su-27. However, this is not enough. As is known to all, stealth aircrafts can strike important enemy nodes while greatly reducing the possibility of detection. Some aircrafts even got shot down before they found them. So the Airforce of PLA asked the engineers of Shengyang research centre and Chengdu research centre to creat a stealth fighter. Though Chengdu finally won the bid, Shengyang shenyang offered some blue prints. This fighter is based on one of them.