Abstract: An observation on fecal egg count with thick-sediment smear method was carried out in 10 schistosomiasis japonica cases in Lumu Commune Wuxian County neatfSuzhou City. 3 counts monthly for 16 successive months were done in each patient. The data were)transferred to logarithmic values and treated with analysis of variance method. Result showed there was no significant difference between the geometric mean values of the fecal egg counts detected in different months, but significant difference was found; between the geometric mean values of the fecal egg counts in individual patients. It is presumed that the amount of schistosome eggs expelled in feces was more or less constant in a certain period of time. Fecal egg count seemed, therefore, practical in the study of epidemiology and surveillance of control effect of schistosomiasis japonica, and may be used freely in any month.