Abstract: As a production-study-research team, we solved the key problems affecting the petroleum geological conditions, and petroleum resources potential evaluation of the Permo-Carboniferous strata in Yingen-Ejina basin. Several new propositions about the formation and evolution mechanism of the basin, the distribution of sedimentary system and sedimentary facies, and source rocks have been established based on the theory of basin mountain coupling, as well as the geological and geophysical technology. The Yingen-Ejina and its surrounding area is a typical rift basin formed in Permo-Carboniferous period, and the source rocks are mainly deposited in the neritic shelf environment of Late Carboniferous and Early Permian. We found many sets of large thickness, stable lateral distribution, with little regional metamorphism, and mature-to-high-mature source rocks in the Permo-Carboniferous formation, accompanied by medium-to-high abundance marine organism and II type kerogen. Geochemical characteristics of natural gas and crude oil from the Upper Paleozoic weathered crust have significant relation with that of the Carboniferous source rocks. In addition, we forecasted the prospecting potential, favorable prospecting areas, and the relative benefit areas in the Permo-Carboniferous formation.