In a seroepidemiological study in several areas of Korea, the ELISA technique was performed to determine prevalence of some important helminthic diseases in our nation during March $15^{th}$ to June $30^{th}$. 1991. In this survey the serum antibody positive rates of anisakiasis, toxocariasis, clonorchiasis, paragonimiasis, cysticercosis, and sparganosis were measured. Among, 6,704 cases examined, 19.7% showed positive antibody titer at least one of the six items studied. Overall positive antibody rate was 8.1% in anisakiasis, 5.6% in toxocariasis, 3.6% in clonorchiasis, 1.7% in paragonimiasis, 4.5% in cysticercosis, and 2.6% in sparganosis respectively. In Pusan port southeastern part of Korea, antibody positive rate of anisakiasis was 2.9%, and clonorchiasis was 2.8% among 450 examine. In TaeJ$\check{o}$n city, central part of Korea. toxocariasis(6.7%) and anisakiasis(3.7%) showed high serologic positive rate. Of the 875 persons in Chunche$\check{o}$n gun(=province), northern central rural area of South Korea, anisakiasis was revealed as 3.4% seropositivity. In Tonghae port, eastern coast of South Korea. 9.9% of population examined showed positive antibody titer in anisakiasis. Of the 1,122 persons examined in Southern part of Cholla-Namdo(Southwestern coastal area of Korea), anisakiasis was 16.9%, cysticerocosis was 12.7% and the paragonimiasis was 3.3% respectively. In some localized area of Cholla-Pukdo, anisakiasis was 9.3% and cysticekosis was 4.3% among 702 cases examined. In some localized area of Kyungsang-Pukdo, anisakiasis was 10.6%. and toxocariasis was 16.1% among 900 cases examined. And finally, in Cheju-do, southern island of Korea, anisakiasis showed high positive rate(6.7%). Because cross reactions between related helminth group may disturb the analysis of these data, use of further developed techniques such as EITB(enzyme-linked immunoelectrotransfer blot) was considered as a essential tools for the study. We thought that probably most of the positive cases of cysticerosis were taeniasis cases. We can't rule out taeniasis even though EITB was employed as far as crude worm extract or cystic fluid of cysticercus was used as antigen. It was well Known that toxocariasis and anisakiasis also showed cross reactivity. However, the data presented here focus on seropositive rate of several helminthic diseases in Korea, not true prevalence rate of helminthiases, and to wait for more expensive purified antigen in sufficient amount for epidemiologic use is not necessary because increased immunologic sensitivity had little effect on epidemiologic sensitivity. We, here, suggest that ELISA should be applied as soon as possible to the evaluation of prevalence of tissue invading parasitic diseases, and a review of the antibody positive rate obtained in this study would be a basic data for controlling program of parasitic diseases in Korea.