Objective: Enterococcus faecalis Gr17 is isolated from Chinese traditional fermented sour fish. It can be metabolized into a new broad-spectrum IIa bacteriocin enterocin Gr17， which has great application potential as a functional strain of fermented food. However， when the strain is used in the actual fermentation environment， it will inevitably face various stress conditions. Acid stress is one of the main stress factors. The purpose of this research was to investigate the effects of different acid stress conditions on the growth and bacteriocin biosynthesis of Gr17. Methods: On the basis of screening the acid stress parameters which could positively affect bacteriocin biosynthesis， the expression level of genes related to bacteriocin biosynthesis under the condition was determined and the influence mechanism was preliminarily analyzed. Results: The results showed that the cell density of Gr17 decreased with the decrease of pH value at the condition of pH 4.5~6.5 compared with the normal growth condition of pH 7.0. Under the condition of pH 5.0~6.5， the secretion and synthesis of bacteriocin was increased. Acid stress at pH 5.5 could significantly increase the secretion and synthesis of bacteriocin. Under these conditions， there was no significant change in the gene expression of ABC transport system associated with bacteriocin biosynthesis in as-48E， as-48F， as-48G and as-48H within 48 h of treatment. The expression of self-induced peptide gene entIP in quorum sensing regulation system increased significantly at 8 h. The expression of two-component genes entPK， entR and bacteriocin coding gene entGr17 increased obviously at 12 h. Conclusion: Based on the above results， it is speculated that acid stress at pH 5.5 could promote the secretion and expression of self-induced peptides， positively regulate quorum sensing system， thus increasing the synthesis of bacteriocin. The results of this study have important scientific and practical significance for revealing the regulation behavior of bacteriocin synthesis in the actual fermentation environment at the molecular level， and maximizing the application value of bacteriocin producing lactic acid bacteria in fermentation production.