The Gongdongchong PbZn deposit, located in the western part of North Huaiyang zone (Anhui section), is the largest PbZn deposit in the Dabie Orogen at present. The deposit is a typical cryptoexplosive breccia type, and oreforming fluid shows features of magmatic origin. Field investigation indicates that cryptoexplosion has a genetic link with the quartz syenite porphyry cropped out in the Sunchong area. LAICPMS UPb dating of two zircon samples from the Sunchong quartz syenite porphyry yields two ages of 1284±13 Ma and 1292±12 Ma, suggesting that it was the result of early Cretaceous magmatism. The Sunchong quartz syenite porphyry has high SiO2 (6204%~6930%), K2O (454%~716%), ALK (K2O+Na2O=876%~1001%) and high K2O/Na2O ratios ranging from 0.94 to 2.86, A/NK=117~197, and A/CNK=103~159, suggesting that it can be grouped into weak to strong peraluminous rock. The rock is enriched in LILE such as Rb, Th, U, Pb, and depleted in HFSE such as Nb, Ta, P, Ti. The Sunchong quartz syenite porphyry has highly enriched SrNdPbHf isotopic compositions: 87Sr/86Sr(t) =071129~071323, εNd(t)=-108 to -98, 206Pb/204Pb(t) =17.495~17891, 207Pb/204Pb(t)=15526~15593, 208Pb/204Pb(t)=38257~38547, most zircon εHf(t) values from -171 to -104. This study, combined with geochemical analysis of the Sunchong quartz syenite porphyry, indicates that the magmatic source of the Sunchong quartz syenite porphyry should be similar to that the upper part of threelayer crustal structure in the Dabie orogen with addition of minor mantle material, which is represented by the gneiss in the centralsouth Dabie belt. The widely spreading Paleozoic black shale in the South China Block, which subducted into deep crust in the North Huaiyang belt, may constitute an ideal source region for the oreforming magmatic rocks.