In order to find a way to reverse the colistin resistance of bacterial,we investigated the effects of efflux pump inhibitor carbonyl cyanide m-chlorophenylhydrazine(CCCP) on the colistin resistance of Salmonella isolates with different resistance mechanisms. PCR and matrix-assisted laser desorption ionization time of flight mass spectrometry(MALDI-TOF-MS) were used to identify the clinical isolates of Salmonella.The minimal inhibitory concentration(MIC) of colistin against Salmonella was determined by broth dilution method.The resistant mechanism of Salmonella isolates to colistin was analyzed by routine PCR and whole genome second-generation sequencing.The reverse effect of CCCP on the colistin resistance of Salmonella isolates with different drug resistant mechanisms was analyzed.The results showed that a total of 32 Salmonella strains were identified. Eight colistin-resistant Salmonella isolates were randomly selected as the test strains,four of which were mcr-1 positive,the other four strains were mutants of twocomponent signal transduction system PhoPQ and PmrAB related genes.After adding CCCP,the MICs of colistin against 8 Salmonella isolates decreased significantly( the MIC reduced by 1/4 096 ~ 1/256).CCCP can reverse the resistance of Salmonella isolates mediated by plasmid and chromosome two-component signal transduction system.