Abstract: Infectivity of 49 strains of Trichoderma spp.,which cause green mold epidemics on edible fungi,were investigated.The results showed that different Trichoderma spp.had varying infectivity and that infection by Trichoderma on mushrooms differed from plant pathogens.The most infective strain of Trichoderma spp.for mushrooms could be less infective to plant pathogens,indicating the specific infectivity of Trichoderma spp.This paper also discusses the infective mechanism of Trichoderma spp,as the results showed that Trichoderma could kill edible fungi’s mycelia via lysing cell walls,entangling,etc.;Trichoderma spp.fermentation fluid could depress mycelium growth of edible fungi and plant pathogens;and Trichoderma spp.produced chitinase did not directly associate with the infectivity.