Abstract: The Huaziyu magnesite deposit, situated in Haicheng, Liaoning Province, is formed in the Paleoproterozoic Era. The ore formation is the magnesian marble in the third member of Dashiqiao Formation, Liaohe Group. Through the analysis of trace elements in the magnesian marble and the research of lithofacies paleogeogarphy and paleoclimatic environment of Dashiqiao age, the metallogenic model of Huaziyu magnesite deposit is summarized as follows:The ore material was derived from the water containing rich magnesium in the dry and hot lagoon basin. With constant evaporation, the primary magnesite ore bed deposited gradually. The later regional metamorphism enriched the primary ore bed. The super large magnesite deposit of sedimentary metamorphosed type was then formed.