In Korea, paragonimiasis is one of the most important endemic parasitic diseases with significant clinical relvance. Since 1917 when Kobayashi has reported a high infection rate(88.0%) of paragonimus metacercariae among crayfish, an important intermediate host, Kanghwa-gun has been known to be a hyperendemic region of paragonimiasis. The present authors carried out an epidemiologic studies to obtain some current informations on the change in epidemiologic aspects of paragonimiasis in Giljeong-ri, Yangdo-myun, Kanghwa-gun, the most hyperendemic region. The infection status of Paragonimus metacercariae in crayfish have been examined. And a total of 392 students of Kangnam Middle School was examined by the intradermal test with Paragonimus antigen. In order to detect Paragonumus egg from the positive reactors, the fecal and sputum examinations were performed. As shown in Tables 1 and 2, there are marked reducing tendencies in the infection rate in crayfish and in the average number of metacercariae per crayfixh examined; 66.2% and 17.2 in 1981, 59.6% and 8.4 in 1984 and 20.0% and 0.6% in 1987, respectively. According to Table 3, 7.1% of the students showed positive reaction to Paragonimus autigeu with the sexual distribution of 8.0% in male and 6.0% in female. However, no Paragonimus eggs were found from the positive reactors by the fecal and sputum examinations.