Abstract: The inhibiting effects of 4 toxic mushroom strains (Amanita virosa Lamb. ex Secr., Amanita muscaria (L.ex Fr.) Pers. ex Hook., Lepiota clypeolaria (Bull. ex Fr.) Quil., Lactarius vellereus (Fr.) Fr.) and their toxin on Cytospora chrysosperma (Pers.) Fr. were studied. The results show that the strains A. virosa and L. clypeolaria have inhibiting effects on the growth of C. chrysosperma, and the inhibiting effect of the former strains is better. In the antagonistic indoor experiment, C. chrysosperma had no inhibiting effect on the growth of A. virosa, but had growth-promoting effect instead. The growth-promoting effect is the highest at the 74th hour, at the same time the inhibiting rate of A. virosa to C. chrysosperma is the highest too. L. vellereus has no inhibiting effect, but has a growth-promoting effect on C. chrysosperma. The inhibiting rates of crude toxin extracts of 4 toxic mushroom strains to the growth of C. chrysosperma mycelium are all 100, and those to spore sprouting are 93.36--97.29。