Abstract: Release of artificial Trichogramma to control the pine caterpillar Dendrolimus punctatus Walker has been taken since 1980. The treated area of pine stand of field experiment was increased to about 1,000mu in 1984. The results of the experiments showed that the area of pine stand treated with artificial Trichogramma and with natural Trichogramma gave significant egg parasitism of 51.17+8.6% and 49.51±14.15% respectively. Both of them were much better than that of untreated check. That was 1.5±1.98%. So that the capacity of host location and parasitic effectiveness of artificial Trichogramma were comparable and in some respects superior to natural Trichogramma.Some characteristics of the artificial Trichograrnma were investigated at the same time: (1) Preferences for different vertical altitude of the host plant (pine); and (2) preferences for lower versus upper parts of the tree.