The Tongling area is one of the largest copper—gold mineralized areas in China．The genesis of the intrusive rocks in this area is still controversia1． The intrusive magmatism in this area has been discussed in term s of petrology，m ineralogy，petrochem istry and isotopic geochem istry． M ixing textures of the magma were first discovered in the intrusive rocks from the Tongling area．The intrusive rocks contain a few mafic m icrogranular enclaves． These features suggest that the magma mixes homogeneously， belonging primarily to chemical m ixing． The Sr—Nd isotopic characteristics also reflect the magma m ixing． The high—K calc—alkaline—shoshonite roc k assoc iations indicate that this area had a thickened continental crust or was an orogenic belt with a mountain root in the early Yanshanian period，and that the magma should be generated as deep as 5 5 km or below． The magm atism is related to the subduction of the Izanagi plate under Eurasia and lithospheric delamination． The delamination of continental lithospheric mantle resulted in adiabatic upwelling of hot asthenosphere and generation of basalt m agma by decompressional melting．The basalt magma underplated and heated directly the lower crust to produce syenite m agma．The basic magma involeved in the m agma m ixing is evolved basalt m agma．Simulation of magma m ixing has demonstrated that the intrusive roc ks are primarily aproduct of m ixing of three kinds of end- member magmas- basalt magma，syenite magma and granite magm a．M ixing of basalt and syenite magmas in magma chambers of the lower crust can produce gabbro-——syenite assoc iations (monzogabbro，pyroxene diorite，pyroxene monzodiorite and monzonite)． Diorite— monzonite magma formed in the lower crust ascends to the middle crust and high temperature of the diorite—m onzonite magma can make the m etamorphic rocks in the m iddle crust melt partially and generate granite magma．Similarly，mixing of diorite—monzonite and granite magm a can produce m onzod iorite—granod iorite assoc iations (monzod iorite，monzonite，quartz monzonite，granodiorite)．