Abstract: According to the low grade and low recovery rate of sulfur concentrate in the flotation process of Meishan iron ore, the mineralogy characteristics of sulfide minerals contained in the raw ores and the flotation concentrate were analyzed in detail using Mineral Liberation Analyzer (MLA) combined with chemical analysis and X-ray diffraction (XRD). The embedded characteristics, particle size distribution and the liberation degree of pyrite, which was the mainly recoverd mineral, were basically determined. It was found that the coarse granularity of raw ores and insufficient liberation of pyrite were blame for the poor separation results and the high sulfur content in the iron tailing. Regrinding and re-concentration of rough flotation concentrate was proposed to solve this problem. The above research could provide a theoretical basis for the optimization of sulfur flotation process in Meishan Iron Mine.