The Indosinian magmatism in the Qingchengzi ore concentration area resulted in the formation of the Shuangdinggou batholith and quartz monzonitic porphyry veins. Based on the petrographic characteristics, the Shuangdinggou intrusion can be classified into two facies zones: the main lithofacies and the central lithofacies. The main lithofacies contain abundant mafic microgranular enclaves and show unbalanced textures, displaying the characteristic of magma mixing. Geochemically, the major oxide contents of the enclaves and their host rocks possess better linear relation in the plot. The REE and trace elements patterns of the enclaves and the host rocks are similar, suggesting that they display the exchanges and equilibrium of elements between the enclaves and the host rocks. The main lithofacies of the Shuangdinggou intrusion has similar geochemical characteristics as the high BaSr granite, and likely originated from magma effect of melts from partial melting of thickened lower crust and magma of enriched mantle. The central lithofacies was formed by the fractional crystallization of feldspar, hornblende, bitite, etc. Quartz monzonitic porphyry might be the hypabyssal phase of Shuangdinggou intrusion and they both have the same source and genesis. The formation of the PbZn or AuAg deposits in the Qingchengzi ore concentration area may be related to the quartz monzonitic porphyry which evolved from magma mixing.