Abstract: The lithology of Shawan reservoir in Sikeshu sag in Junggar basin is mostly medium?fine sandstone, conglomerate in some areas. The reservoir space is dominated by primary porosity, with secondary pores in local areas. The pore throat types of Shawan formation were mainly classified as Type Ⅲ and Type Ⅳ by the characteristics of mercury injection curves and the appraisal of thin?sections. The porosity model is established by geophysical well logging and mathematical methods. Compared with the model developed by single well logging parameters, the correlation coefficient of the new model can be improved by 20%, based on which the study of relation between the petrophysical properties and sedimentary microfacies indicates that both do have certain relationship. The branch channel of braided river delta and fan delta are advantageous facies with good physical properties of the sands. According to the physical property, pore structure and sedimentary facies, the reservoir type in the study area is classified as Type Ⅱ and Type Ⅲ, and evaluated that Shawan reservoir is of good petrophysical property at the whole