Abstract: In order to efficiently and comprehensively utilize a complex polymetallic sulfide ore in Qinghai，find out its ore properties and formulate a reasonable beneficiation process，the process mineralo⁃ gy of the ore was studied. The results show that the lead and zinc in the ore are mainly sulfide. The distribu⁃ tion rate of lead in sulfide is 95.78%，and the distribution rate of zinc in sulfide is 92.37%. The galena in the ore is mostly irregularly distributed in blocks，and the particle size distribution is uneven. The dissemi⁃ nated particle size is finer than that of marmatite. The content of -0.074 mm particle size accounts for 96.95%，and the content of -0.038 mm particle size accounts for 62.82%. The marmatite is mostly granu⁃ lar，and the particle size distribution is relatively uniform. The average particle size is 0.062 mm，of which the content of marmatite -0.074 mm is 67.68%，and the content of-0.038 mm is 39.95%. The useful miner⁃ als in ore are mainly sulfides，which are easy to recover.

Key words: mineral composition, monomer dissociation degree, crystallite dissemination size, occur? rence state