Objectives：In order to investigate the controlling factors of different pore structures in tight sandstone gas reservoirs and the difference of internal fluid seepage behavior. Methods:Study the reservoir pore types and percolation characteristics of He 8 reservoir in the southeast area of Sulige from qualitative to quantitative perspective respectively by cast thin section, conventional mercury injection nuclear magnetic resonance and gas—water relative permeability. According to the relative content of dissolution pores and intergranular pores, the reservoir can be divided into four categories: intergranular pore, dissolution pore— intergranular pore, intergranular pore— dissolution pore, dissolution pore, and also analyzed the movable fluid characteristics, gas—water relative permeability characteristics of the four kinds of reservoirs.Results:Diagenesis difference is the main factor leading to different pore structure types of reservoir. The pore structure of the reservoir with different pore types is significantly different. From intergranular pore dominant type to dissolution pore dominated reservoir, reservoir pore structure characteristics have obvious improvement trend, the saturation of movable fluid increases obviously, and the disturbance degree of gas and water gradually increases, the sensitivity of gas permeability on water saturation is also increasing.Conclusions:The type of intergranular pore and dissolution pore mixed reservoir is a widely developed reservoir type in the study area, the sedimentary microfacies play an important role in controlling the distribution of reservoirs in different pore types.