Abstract: By using core observation, thin section identification and various analysis test data of JingBian gasfield, the research of pore structure has been carried out. The research results show there are mainly 4 kinds of pore types, such as intercrystal pores, intercrystal solution openings, cream salt crystal die hole and solution pores, and 7 kinds of fracture types, such as diagenetic shrinkage joint, anhydrite hydration expansion crack, and dissolved seam, karst collapse sewing, pressolution sewing, breccia seam, structure seam developed in the weathering crust reservoir of JingBian gasfield. Chart observation and statistics show that the rock aperture large cream salt crystal die hole and solution pores are favorable for oil and gas enrichment, while diagenetic shrinkage joint and dissolved seam can make the reservoir effectively be communicated and then improve gas well productivity. The general pore-throat combination of gasfield reservoir is the fine pore- small throat type, in which the pore structure of main producing layer, coarse pore-large and medium throat type, is good.