The Huanggang-Ganzhuermiao ore belt of east Inner Mongolia is tin- polymetallic ore belt i.n Southern Da Hinggan Mountains. Data of major and minor elements in magnetite, cassiterite, galena and sphalerite from ore deposits within this ore belt suggest that these ore deposits are of skarn， hydrothermal, porphyry and grei.sen types related to Yanshanian magmatic activity and that iron in ores came from regional Permian marine interme- diate-basic volcanic rocks whereas partial lead and zinc from Permian geo- syncli顶c sediments. Studies also indicate that galena and Sphalerite in tungsten-tin deposits related to Yanshanian subalkaline granite diffei obt}i- ously from these minerals in lead-zinc deposits associated with Ya}zsha}lian intermediate-acid granitoids i.n contents and ratios of minor elements.