Objective To investigate the effects of different drug resistance genes on the growth adaptability and virulence of carbapenem-resistant Klebsiella pneumoniae. MethodsThe carbapenem resistance genes (blaKPC, blaNDM, blaVIM, blaOXA, blaIMP) and β-lactam resistance genes (blaTEM, blaSHV, blaCTX, blaLAP) were amplified by PCR, and the genotypes were determined by sequencing. Seven housekeeping genes, including rpoB, gapA, mdh, pgi, phoE, infB and tonB, were amplified and sequenced to determine the genotypes and obtain the ST types of strains. According to the different carbapenem resistance genes, the strains were divided into different groups, and then cultured at different concentrations of imipenem (0 mg/mL, 2 mg/mL and 8 mg/mL), the growth curve was drawn to compare the growth adaptability of the strains in each group. According to the C. elegans infection model, infect C. elegans with carbapenem-resistant Klebsiella pneumoniae, the survival curve of C. elegans was drawn to compare the virulence of each group of strain. Results The growth adaptability of strains in all groups was similar without antibiotic pressure. In 2 mg/mL imipenem medium, the growth adaptability of blaKPC+blaNDM group and blaIMP+blaOXA group in the dual resistance gene groups was the strongest, while that of blaIMP group in the single resistance gene groups was the lowest, and the difference was statistically significant. In 8 mg/mL imipenem medium, blaKPC+blaNDM group and blaNDM+blaOXA group had the strongest growth adaptability, which was stronger thanbla KPCgroup and blaOXA group, respectively. Among the single resistance gene groups, blaOXA group had the weakest growth adaptability, while blaKPC and blaNDM had the fastest growth, and the differences were statistically significant. In the absence of antibiotic pressure, the virulence of each group was different. The survival curve of blaKPC group, blaKPC+blaNDM group and blaIMP+blaOXA group shifted to the right, the median survival time of C. elegans was prolonged, means that the virulence of strains was weakened. The survival curve of blaIMP+blaNDM group shifted to the left, the median survival time of C. elegans was shortened, suggested that the virulence of strain was enhanced, and the difference was statistically significant. Conclusion Carrying different drug resistance genes and carrying single or multiple drug resistance genes have different effects on the growth adaptability and virulence of strains