CS-1170 was used for treatment of 26 children who were diagnosed as bacterial infections, and a response rate of 88% was obtained as the drug was effective in 15 of 17 determinable cases. In our evaluation, daily dosage of 75 approximately 270 mg/kg (100 approximately 200 mg/kg in the majority of the cases) was divided into 4 doses, and administered intravenously by one-shot injection over a 10-minute period. The period of drug administration ranged from 1.5 to 25.5 days, but in most cases it was 3 to 6 days. Elevation of GOT and GPT as a side effect of the drug was seen in one case (3.8%), which was reverted to normal level upon cessation of the drug administration.