Abstract: Based on analysis of individual well sedimentary facies with numerous seismic data, logging data, paleobiologic data and other test data integratedly, the sedimentary styles of facies, shape and distribution of sandbodies were clarified and sedimentation variation principles and control factors of sedimentation in Middle Jurassic Xishanyao and Toutunhe Formation were discussed in the Sangequan area of Junggar Basin.Results showed that delta and lake deposits were occurred under warm and humid climate in Middle Jurassic, which was dominated by powerful distributaries channel deposit.When water retreated southward there was large proportion of swamp developed on delta plain.Sangequan area becomes a important target due to its close to western well Pen-1 source sag and is rich in good quality sandbody in the west and south.