Abstract：In order to screen the biocontrol strains which can be used to control capsicum blight，in this study，an endophytic bacterium strain S39 was isolated from a pepper plant，and the inhibitory effect of strain S39 and its metabolites on Phytophthora capsicum was determined by plate confrontation method and Oxford cup method．The antibacterial profile，disease prevention and growth promotion effect of strain S39，the effect on rhizosphere soil microbial population and its biocontrol factors were analyzed．The results showed that the antibacterial rate of strain S39 against Phytophthora capsicum flat plate was 83.00%，and the antibacterial rate of secondary metabolites reached 75.17%．Moreover，strain S39 had inhibitory effect on a variety of pathogenic bacteria，and the bacteriostatic rate reached 63.80%-86.33%．The greenhouse potting test showed that its prevention effect against pepper blight could reach 75.87%．It had a significant growth promotion effect on pepper plants，and the root growth rate was 21.05%．At the same time，it can increase the number of bacteria and actinomycetes in the rhizosphere soil．It can produce antibacterial substances such as protease，amylase，cellulase，dextran enzyme，etc.，and has a good application prospect as a biocontrol preparation.
