Using the endophytic fungus Aspergillus flavipesCanS-34A of oilseed rape as research material,the antimicrobial spectrum of CanS-34A and antagonistic effect onSclerotinia sclerotiorum were studied through dualculture,and in vitro and in vivo leaf inoculation. The results showed that the strain CanS-34A exhibited inhibitory effect on 16 kinds of pathogens,with the inhibitory effects on S. sclerotiorum, S. minor and S. trifoliorum significantly higher than on other fungi (P<0.05). But there were 3 G- bacterial strains could not be inhibited by CanS-34A. After CanS-34A was cultured in PDB for 6 d,the antifungal effect reached to the peak and pH increased to about 7.3. Different concentrations of fermented liquid of CanS-34A have different inhibition effects onS sclerotiorum and the inhibition rate reached to 60% when 2% fermented liquid was added to PDA media. S. sclerotiorum was inhibited when smeared fermentation broth on leaves in vivo or in vitro.Thus,our results indicated that the strain CanS-34A can effectively inhibit growth of S. sclerotiorum and can be used as a biocontrol agent for controlling stem rot caused by S. sclerotiorum.