Clinical studies were carried out on sultamicillin (SBTPC) fine granule in the field of pediatrics. The results obtained are summarized below. 1. Thirty children with bacterial infections were treated with SBTPC fine granule. The clinical results were excellent in 24 and good in 5, with an efficacy rate of 96.7%. 2. Bacteriological screening identified 26 pathogenic organisms of which 14 were Gram-positive cocci and 12 Gram-negative rods. Eradication rates were 91.7% in Gram-positive cocci and 66.7% in Gram-negative rods. 3. As side effects, diarrhea was observed in 12.9%, loose stool in 16.1% and eosinophilia in 3.2% of the patients. From the above results, it appeared that SBTPC fine granule was a useful drug for treating bacterial infections in the field of pediatrics.