Abstract: Baimangshan，Qingshanjiao and Nanhongchong intrusions in the Shizishan orefield，Tongling area，Anhui province，are composed of pyroxene diorite，quartz diorite and granodiorite，respectively． They are predominantly calc-alkine，alkaline-rich，with higher Ba，Sr contents，and share the following similar characteristics with the high Ba-Sr granitoids：higher Ba，Sr and LREE and lower Y and HREE abundances，distinct Nb，Ta and Ti depletion，and absence of negative Sr and Eu anomalies．It is suggested that crystallization differentiation played an important role in evolution of magmas because they have covariant major elements．Fractionation of P-and Ti-bearing accessory minerals，such as apatite，ilmenite and titanite might result in a decrease of P and Ti abundances．The relative depletion in Y and HREE might be caused by hornblende and／or garnet retention，but not intermediate plagioclase in the source．Initial 87Sr／86Sr(0．7062～0．7101)and 143Nd／ 144Nd(0．5116～0．5121)ratios show EM I-type signature, and are negatively correlated．The regional switching from compression to extension in the early Cretaceous in a post-collisional setting might readily trigger a rapid rise of hot Ba-and Sr-enriched upper asthenosphere material and result in widespread melting of lower crust to generate voluminous magmas in the deep-seated magma chamber．