Hongshuizhuang and the Xiamaling Formation in Kuancheng District, Hebei Province are a set of ancient marine shale. In order to study the organic geochemical and reservoir mineralogical characteristics of the two groups of dark mudstones, two shallow formations were implemented in Kuancheng County and Chengde County respectively, with analysis of the collected samples by X-ray diffraction, scanning electron microscopy, and mercury intrusion experiments. The test results showed that the two sets of formations were mainly composed of Ⅱ1, with high total organic carbon content and high maturity. They were the main source rocks of shale gas in this area. In the mineral composition, the content of brittle minerals in the Hongshuizhuang Formation and the Xiamaling Formation was very high, mainly quartz, and kaolinite was the dominant clay mineral; the characteristics of ultra-low porosity and good gas-bearing performance were both shale gas accumulation in this area, the result provided an important material basis.