Abstract: The character of Ma lake depression Jurassic reservoir shows that the main reservoir composed of delta and river sand bodies of braided river.The pore styles of reservoir include erosional pores,protogenesis intergranular pores and relict intergranular pores.The physical properties of reservoir pore spaces are great variant,belong to middle-low pore and filter bed.The diagenetic compaction and plastic rock debris greatly influence its reservoir property.Finally, according to the evaluation standard of the region,D and B strata sequences of the reservoirs are classified as better sequence,but C and A strata sequences are classified as worse sequences.