Abstract: A survey of intestinal parasites was made in 11 sites of 4 counties of Jinzhong Prefecture. Of 5760 individuals examined, 2778 were found infected (infection rate 47.2%), 73.6% of the infected population haboured one species of parasite, while multiittfection with 2, 3 and 4 species of parasites amounted to 21.2%, 4.6% and 0.8% respectively of the infected population. There was no difference in infection rate between sexes. The infection rate for children under the age of 15 was significantly higher than that for above 15 (P0.006). Of 17 species of parasites detected from 6 705 stool specimens, 6 were helminths (infection rate 33.0%) and 11 were protozoa (infection rate 27.6%). Protozoa and helminths accounted for 46.5%(1583/3 479) and 64.6% (1896/3479) of the total worms respectively. In protozoan infections, the incidence of Endolimax nana was the highest(6.4%),which was followed by Trichomonas hominis (6.8%) .Ascaris was the most common helminth with an incidence of 25%. The infection rate of T. trichiura reached 64.6% in children under 12 years of age. The survey revealed a definite relationship between age and prevalence; besides, family clustering of parasite infections was also evident, especially for Entamoeba coli.