Objective： To screen lactic acid bacteria （LAB） with inhibitory activity against quorum sensing and biofilm formation of Aeromonas hydrophila from traditional fermented vegetables. Methods： Screening and degradation N-acyl-homoserine lactones （AHLs） of LAB was measured using Oxford cup agar well diffusion method， the inhibitory rate of biofilm was determined using the 96-well microtiter plates. The biofilm formation of A. hydrophila was observed by light microscopy and scanning electron microscope（SEM）. Strain AJS2-4 was identified by biochemical tests and 16S rRNA sequence analysis. Results： Strain AJS2-4 with inhibitory activity toward quorum sensing of A. hydrophila was isolated from acid beans in Jixi， Anhui Province. 4 mg/mL crude extraction from strain AJS2-4 degraded the AHLs of A. hydrophila and degradation rate reached 49.36%， inhibited the biofilm formation of A. hydrophila and inhibitory rate reached 32.25%. 8 mg/mL crude extraction from strain AJS2-4 completely degraded the AHLs of A. hydrophila. The crude extraction from strain AJS2-4 remained inhibition activity after treatment at 121 ℃ for 30 min. However， its activity completely lost after treatment with protease. Therefore， the inhibition ingredient of crude extraction from strain AJS2-4 was preliminarily determined as proteins with heat-stable. Light microscopy revealed that crude extraction from strain AJS2-4 inhibited biofilm formation of A. hydrophila. The SEM images also exhibited that crude extraction from strain AJS2-4 not only decreased the production of biofilm of A. hydrophila， but also loosed the structure of biofilm. Strain AJS2-4 was identified as Lactobacillus plantarum by physiology and biochemical test and 16S rRNA sequence analysis. Conclusion： Lb. plantarum AJS2-4 with inhibitory activity toward quorum sensing and biofilm formation of A. hydrophila was isolated from acid beans in Jixi， Anhui Province.