Abstract:[Background] Vibrio alginolyticus infects fish, shrimp, shellfish, and other economic marine animals, which has brought great economic losses to the mariculture industry and posed a great threat to public health and food safety. [Objective] The study aims to investigate the inhibitory effect of Fructus mume on V. alginolyticus and the mechanism, which is expected to lay a theoretical basis for the further development and utilization of F. mume. [Methods] The minimal inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) of F. mume extracts (FME) on V. alginolyticus were determined with the tube double dilution method, the relative conductivity of V. alginolyticus by a conductivity meter, and the nucleic acid leakage, respiratory chain dehydrogenase activity, and biofilm inhibition rate of V. alginolyticus by spectrophotometry. The protein synthesis of V. alginolyticus was analyzed by electrophoresis, and the submicroscopic structure of it was observed under a scanning electron microscope. [Results] The MIC and MBC of FME on V. alginolyticus were 1.953 mg/mL and 3.906 mg/mL, respectively. FME significantly increased the relative conductivity and nucleic acid leakage, significantly reduced the protein synthesis, and had great impact on the submicroscopic morphology of V. alginolyticus. Meanwhile, FME significantly inhibited the biofilm formation and the respiratory chain dehydrogenase activity of it. [Conclusion] The FME coould inhibit and even kill V. alginolyticus by increasing the membrane permeability, inhibiting the biofilm formation, respiratory chain dehydrogenase activity, and protein synthesis of V. alginolyticus.