This paper dealt with the. effects of parasitism and host-feeding for Aphytis sp. in 25 combinations of density. It followed that the functional response of Aphytis sp. was fit for Holling- E curve. The host -feeding increased as the density of parasites increased, but decreased as the density of hosts increased. Furthermore, a new model for parasitism has been set up:Where a' : the lowest searching rate, m: the interference oscillation of searching rate, T'b : the shortest handling time, n: the interferenc...