Background : Methicillin-resistant Staphylococcus aureus (MRSA) is a serious pathogen in healthcare-associated infection and has become widespread in community. Circulating MRSA strains vary depending on the geographic feature or clinical circumstances. We compared MRSA isolates from nosocomial and community-acquired infection in prevalence and molecular characteristics. Methods : S. aureus isolates were collected from pediatric patients who visited the Pusan National University Children\'s Hospital from November 2014 to December 2015. Healthcare-associated MRSA (HA-MRSA) isolates were collected in the neonatal intensive care unit (NICU) by skin swabs for routine MRSA screening of 791 inpatients and by blood culture from patients with S. aureus bacteremia. Community-acquried MRSA (CA-MRSA) isolates were collected from nasal swabs of 34 patients with staphylococcal scalded skin syndrome (SSSS). MRSA isolates were characterized by Multi-locus sequence typing (MLST) , SCCmec typing, and toxin gene detection with PCR. Results : 171 S. aureus isolates were collected from NICU skin swab screening, of which 20 (11.7%) were methicillin-resistant : nineteen were ST 72, one was ST 2084 in the MLST analysis. All four isolates from blood culture of NICU patients were methicillin-resistant and were ST 72. Among 12 community-acquired isolates, ten (83.3%) were methicillin-resistant and belonged to ST 89. All 24 HA-MRSA isolates from NICU were SCCmec type IV, while all CA-MRSA isolates from SSSS patients were type II except for the one which failed typing. Conclusion : The data shows the remarkable difference in molecular characteristics between nosocomial and community-circulating MRSA strains. The high prevalence of CA-MRSA becomes a major health concern as well as HA-MRSA infection.