The strata, tectonics and geochemistry of volcanic rocks in the Early Cretaceous of the Fuxin-Yixian Basin and adjacent area in western Liaoning have some special features. Stratigraphically, the Lower Cretaceous is continuous and complete, but the Jurassic is nearly absent, which reflect that the basin was in a denudation setting before the Yixian period (Jurassic), and was fast subsiding in the Early Cretaceous with a total subsidence of about 7000m. Tectonically, in the Early Cretaceous, extensional faulting kept on, while, at the end of the Late Jurassic, folding and thrusting indicated compression and uplifting. Geochemically, high-Mg basalts in the lower Yixian Formation suggest that they are from the mantle with a complex magma source, which shows a large-scale crustal thinning and uprising of mantle magma in the Early Cretaceous. The above geological characteristics reflect that the crustal thinning in the Early Cretaceous had a direct relationship with mantle process and lithospheric thinning. These results are important to further study of the regional background of the volcanic rocks of the Yixian Formation, magmatism, and the cause of lithospheric thinning in eastern China.