The zinc and tin grade of a carbon-containing high-sulfur zinc tin ore in Inner Mongolia are 1.02%and 0.86%,and the content of sulfur and carbon are 14.02%and 1.68%,respectively.The mineral composition of the ore is more complex.The main useful minerals are sphalerite,cassiterite and pyrite,and the gangue minerals are mainly quartz,chlorite and sericite.In order to determine the rational development and utilization technology of ore,the beneficiation experiment was car-ried out by the pre-decarburization and flotation-gravity combined process.The results showed that zinc concentrates with Zn grade of 45.16%and Zn recovery rate of 71.19%and sulfur concentrates with S grade of 46.92%and S recovery rate of 81.91%could be obtained through pre-decarbonization,mixing flotation of one roughing,one scavenging and one cleaning for zinc and sulfur,and separation and flotation of one roughing,one scavenging and three cleaning for zinc and sulfur.The flotation tailings are reselected by shaking table,and after rough selection,cleaning selection,check and middling reselection,the tin concentrate with Sn grade of 45.52%and Sn recovery rate of 81.99%,and the tin rich middling ore with Sn grade of 3.13%and Sn recovery rate of 11.09%could be obtained.The designed test process solves the adverse effect of organic carbon in ore on flotation,recovers valuable minerals comprehensively,and can provide theoretical reference for the development and utiliza-tion of similar ores.