A major breakthrough in oil and gas exploration has been made in the Lower Submember of Member 4 of Shahejie Formation（Es₄^x）in the Minfeng area，Dongying Sag. However，the systematic research on the hydrocarbon generation potential，biomarker characteristics of source rock，and their environmental significance，as well as the impact of gypsum-salt rock on the maturity of the source rock is insufficient. According to the experimental results of rock organic carbon，pyrolysis，identification of kerogen macerals，and chromatography-mass spectrometry of saturated hydrocarbon，as well as the geological conditions，the Es₄^x source rocks are systematically evaluated. The research results show that：①The organic matters of source rock are mainly sapropel-type I and II1 kerogen with excellent hydrocarbon-generating parent materials. The inter-salt and inter-fan mud rocks could both generate hydrocarbon and are medium or excellent source rocks，which thus could be considered as a potential shale oil and gas development area；TOC log evaluation models of different lithology are established by multiple regression analysis，and the predicted values are consistent with the measured values. ②The upper source rocks have higher C₂₇ diasterane/C₂₇regular sterane and regular sterane/17α-hopane than the lower ones and are mainly inter-salt mud rock in a strong reduction environments with salt water. The lower source rocks are mostly inter-fan mud rocks in a reduction environments with brackish water. The above two kinds of source rocks are bounded by a vertical depth of 4 180-4 200 m and are well developed near paleogullies. ③The source rocks are mature or highly mature. The upper and lower source rocks are bounded by a vitrinite reflectance of 1.0%. The upper source rocks mainly generate oil，while the lower ones are favorable for gas generation through splitting decomposition；the geothermal gradient and vitrinite reflectance of source rock above gypsum-salt rock（mainly glutenite reservoirs）are greater than those under or without gypsum-salt rock.