Korea Parasite Eradication Association alleged in its seasonal spring report in 1975 that 36.8 percent of primary, middle and high school students in Seoul area are infected with parasites. Such a high rate of infection is a result of having used raw excrement for manure. Soil is, therefore, to a large extent infected with parasite eggs. In order to present helpful reference materials for preventing parasite infection in the area where human feces have been used for manure, soil in Seoul area and the suburban districts is sampled at random and then the rate of infection in various areas and the variation of infection rate in the same area are studied. The results are as follows 1) The parasite infection rates the according to districts are, Sootaik-ri 39.9%, Chamsil-dong14.2%, Songpa-dong 13.2%, Sageun-dong 12.8% Chayang-dong 11.4%, Sungsoo-dong 8.5%. The above figures show that the rate becomes higher as the area is farther from the urban and residential districts and nearer to the rural area. 2) The rates of detected parasites according to their kinds are as follows Ascaridae 55.9%, Ancylostomatidae 19.9%, Trichocephalus 13.5%, Trichostrongylus 5.7%, Tenia 3.9%, Enterobius 1.1% 3) The monthly variation of infection rate in the same districts, in the case of Sageun-dong, is, August 25.7%, July 18.9%, June 16.2%, September 15.3% April 12.6%, May 11.3%. The above shows that the infection rate of soil is comparatively higher in the summer season.