Abstract: To identify hybrid vigour how to resist insect damage, a research project was carried out with Pinus thunbergii,p. densiflora,P. tabulaeformis and some natural hybrids between these species in the areas where Matsucoccus matsumurae Kuwana had occurred through comparison in morphology and growth,PCA and peroxidase isozyme analysis. Two hybrid types, 'black densiflora'and 'black tabulaeformis', Were selected. Ten-year old trees of these two hybrid types were at all not attacked by the insect, in contrast, P.tabulaeformis and P. densiflora, which were used as control in the experiment, were damaged at rates 22.9% and 30.7% respectively. These two hybrid typesselected could be extended for commercial plantings to the central and eastern parts of Liaoning Province, China.

Key words: Pinus thunbergii Parl., P. densiflora Sieb. et Zucc., P.tabulaeformis Carr, Hybrid selection, Insect resistance