Background and objective: Klebsiella pneumoniaei s an opportunistic pathogenic bacterium and is considered one of the main causes of nosocomial infection. Hypervirulent K. pneumoniae (hvKp) has emerged as a pathogen of global importance. The current study aimed to determine Extended-spectrum beta-lactamase, carbapenem resistance, and serum bactericidal effect among the clinical isolates and to find the relationship of the above features with antimicrobial resistance. Methods: A total of 90 K. pneumoniae isolates were collected from different clinical specimens. Isolates were diagnosed using routine bacteriological methods and VITEK 2 compact system. Several phenotypic tests including string test, serum resistant, ESBL test, and Modified Carbapenem inactivation method were performed. The antibiotic resistance pattern was compared among ESBL-positive, carbapenem-resistant in both Hypervirulent (hvKp) and classical K. pneumoniae (cKp) isolates. Results: The results revealed that among 90 isolates, 56.7% of the isolates were of classical K. pneumoniae (cKp) type within which 70.6% of them were ESBL positive, 37.3% of them were resistant to carbapenem, and 51% were resistant to serum bactericidal activity. On the other hand, 43.3% were of hvKp type within which 61.5% of them were ESBL positive, 30.8% were carbapenem-resistant and all of the hvKp were resistant to human serum. The rate of antibiotic-resistant among cKp was higher than hvKp isolates. Conclusion: In this study, classical strains were more resistant to antibiotics and the rates of ESBL and Carbapenem resistance were higher compared to hvKp strains. but they were killed by serum bactericidal activities more rapidly.