Abstract: Granite-po rphynes in mid-late Yanshan Period is the ore-forming mother rock of Jinduicheng Mo deposit.Rich in Kand volatile flux such as H₂O,F,and Cl,the rock belongs to the crust-derived granite, and is the resultof granization of andesite porphy rites in Xionger Group and quartzites in Gaoshanhe Formation with high percent age in ore-forming elements such as Mo,in the region.The rock and ore body is dominated essentially by a north-west strike fault.Molybdenite mainly in 2H-type thatex perienced gasification and mid-high temperature is distributed in the center of the ore body.On the edge,2H+3R type moly bdenite was fo rmed in mid-temperature environment.Thus,the porphyry Modeposit was formed.