Antifungal spectrum of fermentation liquid from actinomyces strain 1a was determined by the use of agar diffusion method in the experiment.The results showed that the fermentation liquid had good inhibiting effects against nine common plant pathogenic fungi,among which the best inhibiting effect was against Cylindrocarpon destructans,the diameter of inhibition ring was 22 millimeters.Results of Stability tests showed that it had strong stabilities towards heat and UV-irradiation and should be stored in low temperature,but it easily lost stability in extreme acid-base environment.