Abstract: Based on studies on source, reservoir, seal rocks and traps of petroleum system, thermal evolution of source rock and tectonic evolution of the Kashi Depression are analyzed and modeled. Evolution of the Jurassic petroleum system in Kashi Depression can be divided into primary stage and rebuilt one, with different time and space range in different stages. Different oil space range suggests different exploration techniques. For primary petroleum system in the inner parts of depression, the target should be aimed at lithological traps. But for mountain front belts, the concentration should be structural traps.