Abstract: Objective：To study the drug-resistant mechanism of a pan-resistant Klebsiella pneumoniae (Kpn) strain. Methods：The isolated strain was identified by using Vitek-2 compact automatic system, and antibiotic susceptibility was tested by Kirby-Bauer disc diffusion method and microbroth dilution method. The β-lactamase genotypes and 7 housekeeping genes were detected by PCR and DNA sequencing. The nucleotide sequences of 7 housekeeping genes were determined by multilocus sequence typing (MLST). The phenotypes of extended-spectrum β-lactamase (ESBL) were identified by modified Hodge test (MHT), ESBL confirmatory tests, inhibitor-potentiated double-disc diffusion test and modified ESBL confirmatory test. Results：The strain was panresistant Kpn which carried bla_KPC-2 and bla_CTX-M-15. The sequence type was ST11. The result of modified Hedge test was positive. ESBL confirmatory test showed false negative results, but the modified ESBL confirmatory test was positive. The positive result of potentiated double-disc test using 3-aminophenylboronic acid (APBA) indicated Klebsiella pneumoniae carbapenemase (KPC) producing strain. Conclusion：The pan-resistance of the Kpn strain in this study may be aroused by production of KPC. The inhibitor-potentiated double-disc diffusion test for identification of phenotype should be available to detect KPC and ESBL easily and correctly.