Background: To explore clinical characteristics of epiphyseal acute osteomyelitis in children by comparing with metaphyseal acute osteomyelitis.Methods: A retrospective single-center case-control study of children with acute osteomyelitis of long bone, with positive pus culture, between November 2017 and January 2021 was performed. Medical records, laboratory results, and magnetic resonance imaging(MRI) were reviewed. According to infection location on MRI, observation group comprised patients with epiphysis involvement, and patients with metaphysis involvement constituted control group. All patients were treated with antibiotics combined with fenestration of metaphyseal cortex. Body temperature, inflammatory index, pus culture, number of operations, length of stay, and complications were compared.Results: Forty-three patients were included, 12 in observation group and 31 in control group. Maximum body temperature (39.59±0.67℃ vs. 39.11±0.73℃, p>0.05), leukocyte (16.37±5.50×109/L vs. 18.99±5.57×109/L, p>0.05), neutrophil (10.99±4.39×109/L vs. 12.28±4.02×109/L, p>0.05), C-reactive protein (116.45±66.02mg/L vs. 93.05±60.29 mg/L, p>0.05), ESR (76.17±28.26mm/h vs. 61.48±24.43mg/L, p>0.05), number of operations (3.25±1.71 vs. 2.77±0.76, p>0.05), and length of stay (33.25±8.24 days vs. 32.10±9.24 days, p>0.05) were with no statistical differences. The methicillin-resistant Staphylococcus aureus(MRSA) positive proportion of pus culture in observation group was 50.0% compared with 16.1% in control group (6/12 vs. 5/31, p<0.05). No complication occurred in observation group, while one patient developed knee joint contracture in control group.Conclusions: In pus culture-positive acute osteomyelitis of long bone in children, no significant difference in clinical features between epiphysis and metaphysis involvement. MRSA increased risk of epiphyseal acute osteomyelitis in children.