The effects of non-cyanide reagents or combined non-cyanide reagents,such as sodium sulfite,sodium hyposulfite,lime+ zinc sulfate,zinc sulfate+ sodium sulfide,zinc sulfate+ sodium sulfite etc.,on the floatability of jamesonite and marmatite were studied.The study indicated that the combination of zinc sulfate and sodium sulfite(mol ratio1∶1) is kind of highly efficient depressant for marmatite,the combined reagent can make the lead-zinc minerals effectively separate.The use of the combined reagent can result in a desirable zinc concentrate,and reduce the environmental pollution,is beneficial to protection of ecological environment.