Abstract: Volcanic rocks of mesozoic were widely distributed in Western Liaoning province.Yixian volcanic Cycle of early Cretaceous is divided into four subcycles.From early to late, the magma of Yixian volcanic cycle evolved gradually from basic, inter mediate-basic and intermediate to acidic.The ∑REE of volcanic rocks of Yixian volcanic cycle is high and rich in LREE.The spider patterns are the right-incline and there is a slight low Eunegative abnormality and low Ce postive abnormality.REE characteristics show that volcanic rocks of Yixian volcanic cycle were generated in responsing to lithosphere extension in the continent intraplate orogenic belt.The lithogenesis take partial melting as a major part.