Based on the studies of the influence of sedimentary microfacies and diagenesis on the reservoir porosity， the reservoir porosity of the Member 4 of Shahejie Formation was  predicted， the porosity evolution history was modeled， and the distribution areas of  effective petroleum reservoirs were determined by establishing correlation relationships between the diagenetic intensity indexand reservoir average porosity for various sedimentary microfacies in Shuangqing area of the Liaohe Depression. The results of porosity prediction show that the effective oil and gas reservoirs are distributed in areas with the porosity  larger than 5.8％ in the northern part of the study area. The porosity history simulation results suggest that the reservoir porosity during the early burial period was mainly affected by sedimentary microfacies， while in the late burial period controlled by diagenesis. The absolute error between the predicted porosity and practically measured porosity is less than 2.7％. However， the porefilling material content is up to 1.0％～40.0％，averaging at 21.7％. It means that these kinds of porosity simulating models are suitable for predrilling porosity prediction of reservoirs with higher content of porefilling materials and simulation of porosity evolution history.