Abstract: The pathogen of pepper phytophthora blight, phytophthora capsici, usually degenerates as it is successively transplanted and cultivated indoors during identification of resistance and physiological race, which affects the accuracy of identification. In order to maintain the pathogenicity, four strains were cultivated in aseptic water and solid medium, the colony morphology and pathogenicity were measured every three months. The results indicated that the preservation effect of aseptic water at 16℃ was better than that of solid medium. The four strains all had viability when they were preserved for 24 months, the colony morphology and pathogenicity also did not change. This method of preserving pathogens was simple, economical and reliable, so it might be used for strains long-term preservation.