A total of 1,627 cases of schistosomiasis haematobium had been treated with praziquantel of different dosages by the Chinese Medical Team in Mali. The patients were all confirmed by egg detection in urine examination and were divided into three groups. Group A, 1,187 cases, were each given a single dose of 40 mg/kg of praziquantel. In Group B, 321 cases, were each treated with 10 mg/kg of praziquantel, t.i.d. for two days. In Group C, 119 cases, were each administered with one dose of 50 mg/kg of praziquantel. Three months after treatment, the urine egg negative conversion rates were 88.5%, 96.6% and 89.1%, respectively. It was showed that Group B gave the best efficacy and produced fewer side effects, suggesting that the regime of praziquantel treatment given in divided doses is better than that given at a single dose.