Abstract: A serious of tests of flotation was made based on the characteristics of a certain lead-zinc ore in Langcang, Yunnan province. the valuable elements were lead、zinc and silver, and lead sulfide was used as carrier minerals for recovering silver. A reasonable process and regime of agent was determined: in the condition of the grinding fineness was 75% under 0.074mm, it was used calcium to form high alkaline as a depressant of pyrite, the combined reagent of ZnSO₄+Na₂CO₃+Na₂SO₃ was used to be a depressant of zinc, with the dosage is of (1000+1000+500)g/t; a new collector contains diethyldithiocarbamate and a self-developed chemical called WX-1 was used to collect lead and silver with the dosage is of (50+60)g/t, which can improve the recovery of silver and perfect the difficulty separation of lead and zinc concentration; Copper sulfade was used to active the zinc in the tailing after lead flotation with the dosage is of 800g/t; butyl xanthate was used to be collector with the dosage is of 100 g/t. Throughing the closed-circuit test of preferential lead flotation, it was gained the lead concentrate contain 54.89% lead and 2 498.53g/t, with lead recovery of 90.38% and silver recovery of 84%, zinc concentrate contain 40.46% zinc, with the zinc recovery of 80.98%. Thus effective recovering of lead, zinc and silver can be achieved.