Abstract:Xianxia rock is mass rocks that are obviously controlled by the NE tectonic in Zhejiang and Anhui, with complicated lithology content mainly composed of early medium grain monzogranite porphyritic monzogranite and late medium coarsegrain,fine grained syenogranite, and later intrusded by a large number of vein rocks, such as fine crystal rock, quartz syenite, diorite, andesite, diabase,etc.Zircon UPb age data indicate that early monzogranite emplaced about in 1451~1442Ma,late syenogranite emplaced about in 1317~1308Ma,the late diabase dikes emplaced in 1283Ma. Both periods rocks belong to highly fractionated Itype granitoids, with the characterictic of high SiO2and low P2O5; early monzogranite belongs to the metaluminous, highk calc alkaline series, with the characteristic of strong right tendency REE curve, moderate negative Eu anomalies, enrichment of Rb, Th, U, K,and depletion of Ba, Nb,Sr,P,Ti,etc; late syenogranite belongs to metaluminousaluminum, shoshonitic series, with the characteristic of weak right tendency REE curve, strong negative Eu anomalies, enrichment of Rb, Th, U, K,and strong depletion of Sr,P,Ti,etc. Both rocks show relatively high(86Sr/87Sr)ivalue (0.70807~0.70988) and epsilon Nd(t) values (-8.87~-5.14),two stage Nd model age is between 1.36~1.65 Ga.The Early Cretaceous Diagenesis in Zhejiang and Anhui may be related to the changing of the Pacific plate subduction angle, a tectonic background changing from MiddleLate Jurassic(165±5~145±5Ma)compressive environment into earlyearly Cretaceous (145±5~125Ma) extensive environment, resulting in a highdegree crystallization and differentiation the two stage magma which formed by the partial melting of the ancient Jiangnan orogenic belt crustal and may be contaminatedly the Yangtze lithospheric mantle materials.