AIM:To analyze clinical characteristics of periorbital and orbital cellulitis in pediatrics. METHODS:Fifty-four medical records of pediatrics admitted to the Department of Ophthalmology with a diagnosis of periorbital and orbital cellulitis during the year 2010 were retrospectively studied. RESULTS:Thirty-four cases of periorbital cellulitis and 20 cases of orbital cellulitis were included, with no significant differences in gender, eye involvement and age between the two. Male∶female ratio was 2.6∶1, The highest incidence occurred in the 0-3 year old group(71%). Seasonal distribution appeared to peak in November and January, the predisposing factors were diverse. White blood cell count, neutrophil count and percentage of elevated C-reactive protein in periorbital cellulitic patients were lower than those in orbital cellulitic patients(P<0.01).57% periorbital and 88% orbital cellulitic children were found sinusitis by orbital and sinus CT scans. The isolated pathogens found in pediatric orbital abscess fluid included Staphylococcus aureus, Staphylococcus simulans and Streptococcus pneumoniae.Periorbital cellulitic children were treated with single or two antibiotics, while orbital cellulitis usually required combined antibiotics, and surgical interventions when necessary. CONCLUSION:Children with periorbital or orbital cellulitis are commonly under three years old, seasonal incidence peaks in autumn and winter, upper respiratory infection and sinusitis are the most important predisposing factors. Orbital cellulitis has a more severe infection than periorbital cellulitis, CT scan is useful to differential diagnosis.Antibiotic therapy should have coverage against staphylococcal and streptococcal species, and adjust to different predisposing diseases and microbiology. A timely performed surgery can shorten the course of infection and decrease recurrence.