We conducted clinical studies on cefozopran (CZOP), a newly developed parenteral cephalosporin, for its clinical application in the field of pediatrics. 1. A clinical study was performed on 16 children with infections, including 9 with pneumonia, 1 each with acute bronchitis, enterocolitis, purulent lymphadenitis, 4 with skin and soft tissue infections. CZOP was administered by 30 minutes intravenous drip infusion. Doses varying from 20 to 35 mg/kg body weight were given t.i.d. Lengths of treatment ranged from 4 to 14 days. 2. Clinical efficacies were excellent in 10 and good in 6 cases, with an efficacy rate of 100%. The overall bacterial eradication rate for the pathogenic bacteria was also 100%. 3. Side effect was noted in 1 case with skin rash. Abnormal laboratory test data were found in 5 cases including slight elevations of GPT in 4 cases and GOT in 2 cases.