Abstract: In order to explore the genesis of Qian'echong molybdenum deposit in Xinyang， the electron microprobe data was utilized to mineralogically analyze the metal sulfides， combining them with their regional geologic background and deposit characteristics to provide indications of the genesis of Qian'echong molybdenum deposit. The results showed that the mineralization process of the deposit could be divided into six stages. The electron microprobe data of pyrite showed that the pyrite in the quartz-potassium feldspar stage contained 53.51% S and 46.44% Fe（mass percentage）， and w（Co）/w（Ni） was distributed between 0.18 and 0.82， which is indicative of sedimentary metallogenic pyrite. The pyrite in the molybdenite-quartz stage contained 53.21% S， 46.58% Fe and w（Co）/w（Ni） ranged from 1.01 to 5.68， which shows the characteristics of magmatic-hydrothermal pyrite. Combined with the underlying geological features， it is believed that the Qian'echong molybdenum deposit is a more typical porphyry molybdenum deposit.