Abstract: Based on data processing and qualitative analysis of seven magnetotelluric sounding profile, take Carboniferous-Permian as the main purpose layer, the authors implement oil gas geological investigation in Yingen-Ejin Banner basin. We have established seven gravity magnetoelectricity comprehensive inversion profile drawing in the synthesis information inversion and formation of image. Taken the well drilling, the seismic and the regional geology investigation material as the constraints, we have determined the electrical layer demarcation and the explanation basic principle. We have accurately decided the Mesozoic strata of buried depth and thickness using low resistivity marker accurate boundary of the magnetotelluric sounding inversion electronic resistivity, the second high-lever resistance layer semi-quantitative depicted Carboniferous-Permian's distribution. We have divided the section plane geological horizon, and summarized systematically the strata and electrical characteristics in the research area. Research results show that magnetotelluric sounding is an important way to obtain distributed characteristics of Mesozoic and Paleozoic. In Yingen-Ejin Banner basin's complex geology and desert area bad working conditions，magnetotelluric sounding demonstrated the good exploration effect and the obvious superiority, played the influential role for Carboniferous-Permian oil gas geological investigation in this area.