Abstract: The genesis of sandy conglomerate reservoirs cemented by zeolites is the key problem in the exploration of Permian Jiamuhe formation in Zhongguai swell, Junggar basin. Based on core observation and microscopic analysis, and combined with electron probe microanalysis, the paper analyzes the sedimentary facies and diagenesis, establishes the relationships among sedimentary environment, diagenetic environment and reservoir genesis, and discusses the genesis and mechanism of sandy conglomerate reservoirs of Jiamuhe formation in Zhongguai swell, Junggar basin. The sandy conglomerate reservoirs of Jiamuhe formation show some characteristics of tight reservoirs with low porosity and low permeability and the genesis of the reservoirs can be summarized as 4 points. First, a special sedimentary environment of alluvial fan was the basis of multi-type lithofacies formation. Second, the induction of ephemerally open and alkaline diagenetic environment provided the environment for the early zeolite cementation. Third, multiple and rapid alternation of acid and alkaline diagenetic environments was the key factor of secondary pore formation. Fourth, the long-term and enclosed alkaline environment was the most important reason for the densification of reservoirs. The sedimentary facies of Jiamuhe formation is dominated by fan-margin subfacies-mid-fan subfacies of pluvial-alluvial fan, and 4 types of sandy conglomerates cemented by zeolites formed under the combined actions of 6 sedimentary facies and multiple diagenesis. The reservoirs with the lithofacies of coarse grained-medium compaction-medium cementation-medium to strong cementation-dissolution under the control of underwater distributary channel of alluvial fan margin will be the most favorable reservoirs regionally, which will be the key targets for future petroleum exploration