Since 1975, the studies on in vitro rearing Trichogramma spp., Anastatus japonicus Ashmead, Telenomus dendrolimusi Chu, Dibrachys cavus Walker, Habrobracon hebetor(Say), Bracon greeni Ashmead have been conducted successfully in China. The simulated “host-eggs" are made of polyethylene or polypropylene semispherical capsules, containing artificial diets, in which insectan pupal hemolymph is the main component. Manufacture of simulated “host larvae" are made of small rectangular parafilm of cotton-paper bags, containing artificial diets with insectan pupal hemolymph as the main component. Mass production of in vitro reared Trichogramma spp. and Anastatus japonicus and its utilization in the fields showed good effectiveness in controlling cotton bollworm, pine caterpillars, sugarcane borers and litchi stink bug.