To screen lactic acid bacteria （LAB） with inhibitory activity of quorum sensing （QS） and biofilm formation of Aeromonas hydrophila from Chinese traditional pickled vegetables. Six strains LAB with inhibitory activity to QS of A. hydrophila were screened from 21 strains LAB by the Oxford cup method. Among them， strain DLH513 isolated from pickled cucumbers in Dalian， Liaoning Province， was showed strong QS inhibition. The degradation rate of crude extract from strain DLH513 on AHLs signal molecular was 51.1%， and its inhibition rate of biofilm was 40.9% at the concentration of 16.0 mg/mL. Moreover， it completely degraded AHLs at the mass concentration of 20.0 mg/mL. The inhibitory effects of the crude extracts treated by different proteases on quorum sensing of A. hydrophila was loss， indicating that the crude extract had protein properties. When the crude extract treated at 40~121 ℃ for 30 min， it still had QS inhibition effect， indicating that the crude extract had heat resistance. In the pH range of 3.0 to 4.5， the crude extract of strain DLH513 had QS inhibition effect， it indicated that the crude extract was stable under acidic conditions. The results of light and scanning electron microscopy revealed that the crude extract of strain DLH513 inhibited the formation of A. hydrophila biofilms. The strain DLH513 was identified as Lactobacillus plantarum by physiological and biochemical characteristics and 16S rRNA gene sequencing. The study indicated that Lb. plantarum DLH513 can be used as a QS inhibitor for controlling gram-negative bacteria. It will provide fundamental basis for the development of a novel QS inhibitor for controlling gram-negative bacteria caused food spoilage and food-borne diseases.