Based on core observation, slic e identification and logging data analysis, it is considered that the Triassic reservoirs in Cheguai area, northwestern margin of Junggar Basin, mainly developed conglomerate and sandstone. The accumulation spaces of conglomerate are mainly primary intergranular pores and secondary intergranular dissolved pores, and the accumulation spaces of sandstone are mainly primary intergranular pores and secondary intergranular dissolved pores and intragranular dissolved pores. The Triassic reservoirs in the study area are mainly of medium-low porosity and medium-low permeability in general. The Baikouquan Formation is mainly type Ⅱ and Ⅳ reservoir, and the Karamay Formation and Baijiantan Formation are mainly typeⅡ and Ⅲ reservoir. From the Baikouquan Formation to the Karamay Formation, Baijiantan Formation, the reservoir properties become better, and then become worse again. The reservoir property of upper sub-member of the Karamay Formation is the best, so it is the favorable member of high quality reservoir.