Abstract: Oltipraz is a new drug against Schistosomiasis mansoni and was used to treat mice Schistosorniasis japonica in our laboratory. The results showed that 48 h after oral administraction of oltipraz at a single dose of 900 mg/kg, 97% Schistosomes in mice infected with Schistosomiasis japonica schifted to the liver of the host. About half of these worms returned to the mesenteric veins in 96 h. Infected mice was given oltipraz orally at the dose of 900 mg/kg.d for 3～5 days, and killed in 28 days after the last dose. Over 95% total worm reduction rate was found.Schistosomes in infected mice treated with oltipraz were collected for histological observation. The results showed that the tegument of schistosomes were damaged and host cells invaded into the worm body; and granuloma formation of dead worm was observed.During the treatment, food uptake and body weight of the infected mice were decreased, but regained soon after the cessation of the treatment.