Abstract: This paper deals with the population dynamics of Lenolopa huizhouensis Lu, 1996 parasitic in the intestine of Scatophagus argus (Lin.) from January to December 1992 along the coast of Huangfu in Yuedong, Guangdong Province. The results indicated that the mean intensity, the mean abundance and mean crowding were positively correlated with the body length of the host, but the prevalence was relatively stable, except less 30mm of body length of the host. The longer the body length, the higher the mean intensity were, and vice versa, and so were the mean abundance and mean crowding. The prevalence, mean intensity and mean abundance of infection were irregular changes in different seasons in a year. The frequency distribution of the digenea parasitic in the host indicated that the most hosts were not infected or infected with less parasites, and a large number of digenea parasitic in the host of different group of body length and in different seasons all showed aggregated distribution. The degree of aggregation increased with the increasing of mean density of their population.