Abstract: Yangxin sag is a fault basin which was formed during Meso-Cenozoic Period. In this basin, volcanic activity occurs violently and it is abundant in carbon dioxide resources. Coming from earth mantle, the resources reser-voiring is controlled by discordogenic fault, magmatism and upper mantle bulge. Discordogenic fault is considered as a migration pathway, while the releasing and reservoi-ring of carbon dioxide are under the control of tectonic movement which led to magmatic intrusion and magmatic exhalation in different periods. Various types of traps in Es3, Es4 of Eogene have the beneficial condition of capturing carbon dioxide gas. The intersection of fracture system and buried hill zones are favorable accumulation area for dioxide reservoir.