Experiments on Oncomelania, the intermediate host of Schistosoma japonicum,showed that tea saponin used as the molluscicide is effective on the adult and juvenile snails and the snail eggs. Mortality of 100% was obtained by immersing the mollusca and their eggs in 2.5-5.0mg/L tea saponin solution and of 82%-90% was obtained by spraying the adult snails with tea saponin at density of 5-20 g/㎡ Compared to Niclosamide,tea saponin is much less toxic to freshwater fish. Tea saponin’s easy availability, low price, botanical origin, and nonniques in using tea saponin as molluscicide are detailed.