Abstract: The Enzyme-linked Intraoval Precipitin test(ELIOP) and Indirect Hemagglutination test with a gut-associated antigen (GAA-IHA) were used to observe the kinetics of antibody levels in patients with schistosomiasis japonica before and after treatment with pyr quiton in two different endemic villages. The results showed that the antibody geometric mean reciprocal titer(GMRT) and positive rate decreased significantly in ova-negative patients 3-4 months after treatment; the decrease of GMRT as well as the positive rate of ELIOP in the village where snails had been eradicated were more markedly and earlier than those in the village where snails had not been eradicated, and the antibody level in young age groups tended to decrease more rapidly than that in older age groups. These suggest that the measurement of the kinetics of antibody levels in patients with schistosomiasis before and after treatment, especially in young age group, could be used to estimate the effectiveness of a control program soon after its performance and may be of value for surveilance of transmission in a given endemic area. This paper also noticed that the antibody levels after treatment detected by ELIOP decreased more rapidly than those by GAA-IHA, suggesting that ELIOP may be more promising in seroepidemiologica survey of schistosomiasis.