Abstract: Abstract A survey of human parasites at provincial level revealed a total infection rate of 64.8% in Henan. The data concerning family clustering of 6 species of parasites were analysed, which included Ascaris lumbricoides (infection rate 41.5%), hookworm (20.8%), Trichuris trichiura (8.4%), Enterobius vermicularis (24.5%), Entamoeba histolytica (0.6%) and Giardia lamblia (7.2%)); the result of χ 2 test for binomial distribution of the above 6 parasitic infections showed values of 2338.5072, 8920.1552, 6207.5763, 758.3369, 293.9336 and 895.4514, respectively, all revealing P 0.01, hence very significant family clustering.