Sulfur, as a mineralizing agent, is indispensable to most of the nonferrous metal ore deposits, contributing to the formation of ore mineral. Nowadays, the researches on S mainly focus on tracing the sources of oreforming fluids, whilst little on its initial enrichment in geologic body and its mineralcontrolling activities in mineralization. Through a 10year systematic research on the relationship between S and oreforming processes in more than 40 ore mineral deposits, it is found that all the hydrothermal ore mineral deposits are seated at Srich area. The enrichment of S and the formation of orebearing rock take place in the same time, accompanied by the enrichment of the oreforming elements which forms the initial source of oreforming substance and lays the foundation of ore mineral formation. It is the direct reason that S and oreforming elements in the initial source of oreforming substance are activated, transported, and reenriched This paper sets Yemaquan test area, Qinghai, as an example to elaborate the above results and new discovery. The results of the study on Yemaquan Fepolymetallic deposit, Qinghai Province, show that the enrichment of S in limestone was happened at the same time as the formation of limestone, accompanied by the enrichments of Pb, Zn, and Cu, forming the ore source. The activation, transportation, and reenrichment of S and oreforming elements, which were led by post mineralization, are necessary to oreforming process. The sedimentary environment of ore source is of special significance. This study is of some reference value for researches on oreforming mechanism and exploration geochemistry.