Abstract: Twenty-seven pilot sites were selected from three counties of Beijing suburbs according to different topography and socioeconomic status. Iodine direct smear, Kato-Katz thick smear and adhesive-tape techniques as well as fecal culture method were applied for parasitological diagnosis.Of 13730 residents from the investigated sites, the overall parasitic infection rate was 39%. Ten species of protozoa, nematode, and trematode were found in the population. Among these species, the respective infection rates for Ascaris lumbricoides, Enterobius vermicularis, Trichuris trichiura, and Clonorchis sinensis were 30.7%, 20.1%, 1.3% and 0.1%, respectively. Entamoeba hartmanni, Endolimax nana, and 1odamoeba buetschlii were recorded for the first time in these counties.The highest rate and intensity of ascarid infection was observed in mountainous district and rural areas, however, while comparing with the data recorded in Tongxian in 1978, a marked decrease was noted, probably resulting from, the improvement of economic and sanitary conditions in the suburbs since reformation.