Abstract: Based on the study of reservoir characteristics and key controlling factors for oil?gas accumulation in Neogene Shawan formation in Chepaizi swell of Junggar basin, it is considered that the Shawan reservoir located in the central?eastern Chepaizi swell is dominated by lots of small?scale fault?blocks and fault block?lithological light?oil pools, and distributed in the second member of Shawan formation; while the northwestern part of the swell is dominated by a small quantity of large?scale lithological heavy?oil reservoirs which are mainly distributed in the first member of Shawan formation. Sandbodies, faults and traps of the second member are the main factors controlling the oil?gas accumulation, while lithological trap of the first member is the key factor of the oil?gas accumulation. The sand bodies in the second member are predominantly developed near the slope break belt with an obvious feature of reservoir controlled by the top thin sandbodies. Tensional normal fault resulted from Himalayan movement is another key controlling factor in the second member, which effectively connects Jurassic oil source in Shawan sag and deep traps in Hong?Che fault belt, and meanwhile acts as a barrier. The oil in Shawan formation originated from Jurassic source rocks in Shawan sag and mixed with some oil from deeper reservoirs. The reservoir formed during Quaternary