Abstract: Xiaohulishan Pb-Zn molybdenum deposit is a medium-large scale concealed deposit recently discovered in Beishan area of Inner Mongolia.Its major ore bodies are mainly classified in three facies such as the marginal facies, the transitional facies and the central facies.Metallic minerals are mainly composed of molybdenite, pyrite with the rare metal ores associated.The deposit belongs to the typical porphyry molybdenum-rare metal deposit, and formed in Trias.It is the generation of Indosinian tectonics and magmatic activity.And due to its typical character of ore-forming, there is a big potential for ore prospecting of similar ore deposits.

Key words: Molybdenum polymetallic-rare metal deposit, Porphyry, Geological significance, Beishan area