Abstract: The Baiyinnuoer Pb-Zn deposit in Inner Mongolia is a typical skarn type deposit. However, there is little research concerned with geochemistry and metallogenic dynamics of the ore-forming body. The granitoid rocks that related to mineralization are studied in this article. The results show that the granitoids are high-K calc-alkaline series with enriched LREE and large-ion lithophile elements(LILE) and depleted high field strength elements(HFSE). The origin of magma is the enriched mantle. The mineralization occurred in the post-orogenic extension environment.