Abstract: The oil-gas survey and exploration in Fuxin Basin has a long history. Despite quite a few oil-gas discoveries and even low production obtained from some wells in the beginning, none of them have sustainable and stable production. In 2017, high-yield industrial oil flow was obtained from LFD-2 well in the Lower Shahai Formation of Fuxin Basin, with a daily production of 15.3 m³, achieving a major breakthrough in oil-gas survey and exploration. To further study the stratigraphic characteristics of Lower Shahai Formation in Fuxin Basin, the natural gamma-ray spectrometry logging data are used to analyze the shale content, clay mineral type and sedimentary environment of Lower Shahai Formation in LFD-2 well, which ascertains the shale content and its variation. It is concluded that the Lower Shahai Formation was formed in a sedimentary environment of interactions between oxidation and weak reduction, with weak hydrodynamic conditions (mainly low energy). The study provides a basis for further understanding of the reservoir characteristics of Lower Shahai Formation and contributes to the following oil-gas exploration and theoretical research in Fuxin Basin.