Abstract: OBJECTIVE To explore the clinical and molecular epidemiological characteristics of hypervirulent Klebsiella pneumoniae (hvKp) and carbapenem-resistant K.pneumoniae (CRKP) causing bloodstream infection. METHODS The medical data were collected from the patients who were diagnosed with K.pneumoniae bloodstream infection by clinical blood culture in Guangdong Provincial People's Hospital from Jan 2020 to Jun 2022. Totally 32 strains of K.pneumoniae were included in the study, including 16 strains of hvKp and 1 strain of CR-hvKp. Totally 17 strains were defined as hvKp, and 15 strains were defined as CRKP. The drug resistance genes, virulence genes and capsular serotypes were analyzed by whole genome sequencing. The sequence types of the strains were analyzed by multilocus sequence typing (MLST). RESULTS All of the bloodstream infection patients were complicated with underlying diseases. The invasive procedures were more, and the mortality rate of the CRKP infection patients was higher (P<0.05). The patients were mainly from intensive care unit (ICU), infection department and pediatrics department. The result of sequencing analysis showed that CRKP strains mainly carried with blaKPC-1 and blaNDM-1 drug resistance genes and the virulence genes entA, entB, entE, fepA, fepC, fepG, ompA, xcpR, yagV/ecpE and ykgK/ecpR; K14 and K64 were the major capsular serotypes, and the result of MLST typing showed that ST11 was dominant. While the hvKp mainly carried with the virulence genes such as entA, entB, entE, fepB, fimA, irp1, mgtB, ompA, yagV/ecpE and ybtA; K1 and K2 were the major capsular serotypes; MLST showed that ST23 and ST25 were dominant. 1 strain of CR-hvKp carried with multiple virulence genes and was ST751. CONCLUSION The hvKp and CRKP strains that are isolated from the patients with bloodstream infection carry with multiple virulence genes and drug resistance genes, which brings challenge to clinical treatment of infection and prognosis. The emergence of CR-hvKp poses great threats to the health of patients. It is necessary to strengthen the laboratory test of the pathogen, report in a timely manner after isolation and take active measures so as to reduce the transmission in hospitals.