Abstract:The research was carried out by investigating number of predators and predation capabilities along with mortalities of the pine bast scale (Matsucoccus liaoningensis Tang) inside sampling plot, and by applying the K-value graphic analysis method.It was found that the predation happened mainly on female imago,but seldom on egg sac. Among the predators, such as ladybug, lacewing, mite, stinkbug,ant and spider,the predation capability of ladybug ranks the highest,and the ant the second.The main predator species are ladbug Harmonia axyridis Pallas,Sticholotis punctata Crotch, Exochomus mongol Barovsky;ant Iridomyrmex anceps Roger,and Polyrhachis dives Smith.