Hadamengou large gold deposit inInner Mongolia is one of the important deposit, located in southern margin of Wulashan anticlinorium of Yinshan uplift(west part of the Inner Mongolian earth axis) on the north margin of North China Craton. The gold orebodies mainly lies in the metamorphic rock of Wulashan Group, Archaeozoic erathem., main ore type include gold bearing quartz vein type, gold bearing quartz potassic feldspar vein type, gold bearing altered rock type. ore forming fluid is characterized by intermediate low temperature（160~300℃）, mid low salinity（5%~15% NaCleq）.The gas component of fluid inclusions is dominated by H 2 O and CO 2 , The main anions in the liquid composition are Cl - and SO 2- 4 , and the cations are Na + , K + and Ca 2+ .The sulfur isotope composition of the ore δ 34 S vary from -21.7‰ to 5.4‰, the change range is 27.1‰, average value is -10.6‰，depleted 34 S, indicated the sources of ore forming material are complexity, sulfur isotope composition inherited archean strata, mixed with sulfur in deep sourced ore bearing Fluid. Lead isotopic compositions of the ore, single stage model age, Th/U ratios, μ value vary in a large range, indicated multiple sources characteristics. In plumbotectonic model diagram by Zartman and Doe, the lead isotopic compositions of ore mineral plotted scattered, this demonstrates that the ore lead came from the mixed lead. Hydrogen and oxygen isotopes show that the ore forming fluid was derived from magmatic and small metamorphic water, Late mixed with meteoric water. molybdenite Re Os weighted mean age is386.4±2.7Ma and isochron age is 386.6±6.1Ma of the orestone, which show the main metallogenic epoch is early devonian, later multi phase hydrothermal activity probably superimposed on the early stages. The deposit formed in intracontinental extensional tectonic setting after arc continental collision.