Abstract: Tomato, antimicrobial peptides（AMPs） and tomato Botrytis cinerea were used as test materials.The antifungal effects of CB and D20I-39 on tomato B.cinerea and the relative mechanisms were investigated by plate experiments.The control effects of AMPs on tomato leaves infected by gray mold and the indexes of disease resistance and antioxidation were analyzed by pot experiments, in order to provide reference for AMPs to control tomato gray mold.The results showed that both CB and D20I-39 could inhibit mycelial growth and spore germination of B.cinerea dose-dependently and caused leakage of intracellular nucleic acid and protein in B.cinerea.After treatment of CB and D20I-39,the mycelia of B.cinerea were flattened, shrunken and narrowed.And as the concentration increased, the mycelial folds became more severe and even rupture occurred.In pot experiments, the preventive test demonstrated the control effects of CB and D20I-39 were 96.37%±0.13% and 83.41%±0.17%,respectively and the therapeutic test exhibited the control effects of CB and D20I-39 were 14.86%±0.35%and 59.74%±0.23%,respectively.AMPs could increase the activities of PAL,SOD and the levels of Pro,whereas decreased MDA content.The results indicated that the novel AMPs CB and D20I-39inhibited B.cinerea by destorying cell membrane to exert the antifungal activity,and reduced the incidence and diseases index of tomato gray mold.CB and D20I-39had good control effects on tomato gray mold.