This study was undertaken to evaluate the present status of parasitic infection and swine pen human latrine system in Cheju Do, from July to September 1982. The 663 stool specimens (male 323 and female 340) and 579 scotch tape anal swabs collected from 161 households of 2 areas in Cheju Do were examined. The methods employed were formalin-ether technique for the prevalence rate of various helminthic and protozoan infection, and scotch tape anal swab technique for the prevalence rates of Enterobius vermicularis. In addition to these, questionaire was used to evaluate the present status of swine pen human latrine system and prevalence rates of taeniasis in these areas. The results are as follows ; 1) Prevalence rates of parasitic infections of any kind was 33.9%. It was 35.7% in Cheju City in contrast to 32.1% in North Cheju Gun. The infection rates of Trichuris trichiura was 10.0% and it was the highest prevalence rate in this survey. The prevalence rates of the other parasites were as follows ; Ascaris lumbricoides 2,3%, Hookworm 0.2%, Clonorchis sinensis 0.5%, Hymenolepis nana 1.5%, Entamoeba coli 3.2%, and Giardia lamblia 0.5%. 2) The infection rates of Enterobius vermicularis in 579 peoples (male 285, female 294) by applying scotch tape anal swab technique was 13.1% through the survey. It was 16.9 in Cheju City and 8.5% in North Cheju Gun. 3) The Infection rate of Taenia species by applying the stool examination and making up a question was 19.2%(21.4% in Cheju City and 16.7% in North Cheju Gun). 4) Sexual distribution of the parasitic infections showed slightly higher rate in female than that of male. 5) The positive rates of parasitic infection by the stool examination and questionaire positive cases of taeniasis were higher in 0-9 and over 60 year old than any other age group. 7) The swine pen human latrine systems were used in 46 households (28.6%). 7) Relationship between swine pen human latrine system and taeniasis was not noted.