Abstract: Quantitatively estimating the hydrocarbon generating potential evolution of source rocks is the first problem for petroleum exploration. Using organic matter abundance, organic matter type and organic matter maturity index the authors studied hydrocarbon generating potential evolution quantitatively or qualitatively. It is firstly confirmed that Ejina Banner basin and its adjacent areas develop Permo-Carboniferous source rocks of shallow-marine shelf phase sedimentary mud shale. Research results show that there are three sets of source rocks of Permo-Carboniferous in the areas, such as Amushan Formation, Maihanhada Formation and Haersuhai Formation. The thickness of source rocks are large, and the rocks have higher organic matter abundance. The main type of the Kerogen is typeⅢ. Thermal evolution degree is related to tectonic activity and buried depth. Most of organic matter is in the phase of maturation, which shows that there are favorable hydrocarbon prospects in Permo-Carboniferous in the areas.