〔Abstract〕 Objective To study the expression level changes of virulence genes ofhypervirulent Klebsiella pneumoniaeunder the action of antibiotics with subinhibitory concentration. Methods Disk diffusion method and ViteK2 instrument method were used to determine the susceptibility of the strains to common clinical antibiotics, and the MIC values of the strains to cefoxitin and amikacin were detected by broth dilution method.The serotypes of capsule(K1, K2, K5, K20, K54, K57) and virulence related genes(rmpA,aerobactin,kfu,alls,magA,wcaG,fimH,mrkD) were detected by polymerase chain reaction(PCR). According to the MIC value of the two drugs, the 1/2 MIC, 1/4 MIC and 1/8 MIC subantibiotic concentration gradient of antibiotics was prepared. qRT-PCR was used to detect the change of the relative expression of virulence genes in 1/2 MIC, 1/4 MIC, 1/8 MIC concentrations of cefoxitin and amikacin, and the difference was analyzed by SPSS software. The homology between the strains was detected by MALDI-TOF MS and ERIC-PCR. Results A total of 57 strains ofKlebsiella pneumoniaewere collected, which were sensitive to most of the commonly used antibiotics. PCR results showed that there were 17 strains of K1, 21 strains of K2, 2 strains of K20, 8 strains of K57, and 9 strains of unknown haemorrhagic type.RmpAandaerobactingenes were all positive.17, 21 and 16 strains ofwcaG,kfuandmagAgenes were detected respectively.FimHandmrkDwere all positive. Under the action of subinhibitory concentration of cefoxitin and amikacin, the two antibiotics of three concentrations(1/2 MIC, 1/4 MIC, 1/8 MIC) had obvious inhibitory effects on the two virulence genes(P<0.05), and the inhibition degree of cefoxitin was the highest. The inhibitory effect of 1/2 MIC was the strongest among the three concentrations. Conclusion Hypervirulent Klebsiella pneumoniaeis highly sensitive to commonly used antibiotics. Serotypes K1 and K2 are common serotypes ofhypervirulent Klebsiella pneumoniaethan other serotypes.The virulence gene expression ofrmpAandaerobactindecreased under the action of subinhibitory concentration of cefoxitin and amikacin.