The production and pyrophorisity of iron sulfur compounds in liquid phase were studied in order to get the spontaneous combustion rules of iron sulfur compounds producted by different ways. In the experiment, FeSO4·7H2O, FeCl2·4H2O, Fe (NO3) 3·9H2O react with (NH4)2Sx and Na2S·9H2O respectively,then the pyrophorisity were analyzed by the exothermic oxidation process of sulfuration productions. The results show that, the pyrophorisity of sulfuration productions formed from (NH4)2Sx and dissolvable iron salt is obviously higher than formed from Na2S and the same dissolvable iron salt. With the increase of dissolvable iron salt concentration, the oxidation pyrophorisity of sulfuration productions formed from (NH4)2Sx also increases. There is some pyrophorisity of sulfuration productions formed from Na2S and dissolvable iron salt. But the pyrophorisity is faint relatively.