This paper systematically reviews the history and background of large UAV * s development in China, which includes the first developed simulated target drone, all kinds of substantial pilotless drone and the developing unmanned attack air vehicle. The main technical difficulties and key technologies applied are introduced in detail. The developing journey of all kinds of unmanned air vehicle is formulised. In the end, the importance and development of UCAV in China are also previewed, analysed and plotted.