Secondary pore is one of important types of reservoir space in sandstone reservoirs. It is not difficult to identify secondary pores with the petrographic method. however, it is when quantitative statistics of pore types are to be made, because secondary pores and primary pores were often connected to form into mixed pores resulted from intense corrosion. The paper proposed a method that combines the observed porosity and petrographic statistics, and clarified the samples into "intense corrosion" and "weak corrosion" types, so as to make their statistics respectively. The petrographic method was applied to get accurate statistics of the samples of "weak corrosion" type, while the affects of "intense corrosion" were determined on the basis of a observed porosity, and finally to obtain accurate quantitative statistical data.