Abstract: The Jurassic reservoirs in the Moxizhuang region,Junggar Basin,Xinjiang are characterized by low compositional maturity,abundant debris,low matrix contents and high textural maturity.The pore space types include residual intergranular pores,intergranular solution openings,intragranular solution openings,intercrystal pores and microfissures,of which the former two are main types accounting for 25% and 56%,respectively.According to mercury-injection curves and physical properties of cast sections,the reservoir quality of the sandstones in the Moxizhuang region is mostly constrained by sediment grain sizes,sedimentary facies types,diagenesis and burial conditions.The burial conditions are considered as a basis for the good reservoir quality;diagenesis as a direct control on the reservoir quality,and sediment grain sizes and sedimentary facies types as the most important factors influencing the reservoir quality.The reservoir quality is excellent in the lower submember of the second member of the Sangonghe Formation while worst in the Badaowan Formation.