Abstract: To study the mechanism of bongkrekic acid production by Pseudomonas cocovenenans subsp. farinofermentans at proteome level, data-dependent acquisition (DDA) unlabeled quantitative proteomics technique was used to analyze the protein changes of P. cocovenenans before and after toxin production. The results showed that 25 proteins were up-regulated and 31 proteins were down-regulated in toxin-producing strains. Among them, ABC transporters, response regulatory receptor protein, methyl-accepting chemotaxis protein II were related to bacterial chemotactic signal transduction. And flagellins such as P-cyclin, M-cyclin and FlgE were all related to chemotaxis. It is supposed that chemotactic movement plays an important role in the production of bongkrekic acid. The study on the production mechanism of bongkrekic acid can provide theoretical evidence to decrease the incidence of foodborne diseases.