According to the further study of the stratigraphical system, metallogenesis horizon, geological characteristics of ore deposit and ore control factor in orefield, the authors think that the main Au metallogenesis bed of orefield is Lower Ordovician Laozhai Formation (O<sub>1sub>l), none of the Lower Devonian Posongchong Formation. The Au metallogenesis is mainly controlled jointly by fault, magmatism, unconformity and lithological characters. And the concentration space of ore body is in close relation to the fault and deep magmatism.