Objective: Rainbow trout usually contains more free amino acids and nitrogen compounds， so it is easier to produce biogenic amines. Aeromonas salmonicida was isolated from rainbow trout， and the inhibitory activities of EGCG has been investigated against Aeromonas salmonicida. Methods: Cell morphology，alkaline phosphatase activity (AKP)， intracellular ATP enzyme， extracellular protease content extracellular total protein content were examined to elucidate their antibacterial effects. Results: The minimum inhibitory concentration of EGCG against Aeromonas salmonicida was 0.25 mg/mL. In addition， EGCG has a good inhibitory effect on the biogenic amine-producing of Aeromonas salmonicida， and BAs content decreased with increasing EGCG concentration. EGCG could destroy the cell wall of Aeromonas salmonicida and enhance the permeability of the cell membrane， resulting in the leakage of intracellular AKP， Na+K+-ATPase and protein， leading to the cell pyknosis and death of the bacteria. EGCG could also inhibit the secretion of extracellular protease. Electron microscopy revealed that the structure of the bacterial cells was destroyed and accompanied with induced cells plasmolysis. The inhibition rates of protease in 1/2 MIC， 1 MIC and 2 MIC groups were 9.89%， 34.53% and 40.12%， respectively. Conclusions: EGCG has inhibitory effect on Aeromonas salmonicida from rainbow trout， which provides theoretical basis for the application of EGCG in the preservation of aquatic products.