The Muchen pluton, outcropped with a NNE-trending around Muchen of Longyou County and Shuangxikou of Suichang County in Zhejiang Province, was generated during the late stage of Early Cretaceous（112 Ma）.Lithologically, this pluton comprises mainly of quartz monzonites, with abundant mafic microgranular enclaves（MMEs） of different shapes. The integrated petrology, elemental and isotopic compositions suggest that the MMEs and the host rocks were most likely generated via a process including mixing of depleted mantle-derived mafic magmas and induced felsic magmas by partial melting of crust materials under an extensional setting, and suffered further differentiation during magma ascent.