High precision SHRIMP U-Pb zircon analysis indicates that the Xucun granitoid in southern Anhul，in the southeastem Yangtze Block formed at 82 3±8 Ma． Mineralogical，petrographic and geochemical characteristics indicate that the southern Anhui Neoproterozoic granitoids are peraluminous，S—type or CPG type granodior-ites。 Thev were derived from a clay—poor，plagioclase—rich psammitic source having crutsal residence ages of 1.5～1．7 Ga，similar to the regional Mesoproterozoic Shuangqiaoshan metasediments?The granitoids were generated by partial melting under vapour present conditions at 800～850 ℃．It is suggested that the southern Anhui Neoproterozoic granitoids were formed by crustal anatexis above a mantle plume at～825 Ma in South china rather than formed during the early Jinningan orogeny as previously thought? Kev words：Neoproterozoic；granitoids；U—Pb zircon geochronology；element geochemislry；Nd 1sot叩 SOllthern Anhui