Abstract: Fecal examination using direct smear and iodine staining was carried out in 51 883 subjects in twenty counties of Guangxi in 1987-1989. Altogether 771 subjects were found to harbor the cysts of Entamoeba histolytica , the average infection rate being 1.5%. The highest infection rate (2.0%) was at the age group of 30 to 39. A total of 1 641 subjects were found parasitized by the cysts of Giardia lamblia , the average infection rate being 3.2%. The infection rate was significantly higher in males (3.5%) than in females (2.9%) ( P 0.01). The highest infection rate (5.9%) was at the age group of 5-9. Entamoeba coli, Endolimax nana, Iodamoeba buetschlii,Entamoeba hartmanni, Trichomonas hominis and Balantidium coli were also detected in the survey. Water pollution is the essential cause of prevalence of protozoan infections; evidently, environmental sanitation should be stressed in control practice.