The oxidation produce of sulfide mineral is polysulfide(Sn2-), in the area of sulfide mineral,and there are various of sedimentary organic compounds, the sedimentary organic compounds includes carbonyl compounds.The reaction channel between polysulfide and the electrophilic organic compounds is the main sources for organic sulfur compounds, the organic sulfur compounds containing CS2, COS and so on.According to our experimental, CS2 formation by the reaction of polysulfide with low molecular weight organic acid.the CS2 may be a precursor for atmospheric COS, for instance, the reaction of CS2 with OH, CS2 + OH → COS +HS(k=l.9×1013cm3sl, at 296K).