Based on the research of rock slices, the rocks of Cretaceous and Jurassic in the southern marlin of Junggar Basin have the main character of low compositional maturity, low texture maturity, low cement content and weak corrosion. The sand of Xishanyao Formation and Baodaowan Formation, which are coal measure strata, are characterized by high plastic debris content, high kaolinite content and high pressolution diagenetic compaction. The main pore types of reservoir are intergranular pore, intragranular pore, cement emposieu and micropore. According to the reservoir characteristics and the distribution of high quality reservoir, Sikeshu sag and Malasihutubi anticline are favorable exploration area of Cretaceous and Jurassic.