K. pneumoniae is gram-negative, facultatively anaerobic, bacilli. It is a member of Enterobacteriaceae. It most commonly causes pneumonia, bloodstream infections, meningitis, liver abscess, urinary tract infections or kidney abscess. The polysaccharide capsule is the notorious virulence factors. The virulent strains in the community are different from those causing healthcare-associated infections. In hospitals, K. pneumoniae obtained ESBL and become multidrug resistant. Recently, emergence of carbapenem-resistant K. pneumoniae poses great threat to healthcare system.