Abstract: A comprehensive survey on schistosome infection of the inhabitants and Oncomelania snails was made to evaluate the effect of the schistosomiasis control in 99 production brigades of 10 counties in Jiangsu Province.. Results showed that there existed significant changes. The positive rate of stool examination was reduced from 17.959% in 1970 to 1.09% in 1980. There was no new infection of the children aged below 10 in 92 % of the examined brigades. The reduction rate of the snail infested area was 98.83%. Among the 99 brigades, Oncomelania snails could not be detected in 55. Schistosome infected snails could be found only in 2 brigades. The mean snail density was reduced to 0.005/ square Chinese foot.However, there are still some problems. The remained patients, although few in number, are late and complicated cases mostly. The remained snail infested places possess the nature of "small, scattering and difficult to detect". Further effort is needed to eradicate schistosomiasis.This paper also considered that the new infection of children below 10 years of age may provide a sensitive index of the level of transmission and may be used as an important epidemiological measurement in the survey of anti-schistosomiasis effect.