Abstract: This paper studied the damage of Pineus armandicola on No.222 Forest Farm, Dongchuan District of Kunming City, Yunnan Province.The result showed that the representative value of the damage grade of Pineus armandicola was possitively related to the loss ratio of the volume.This corelationship could be expressed in a regression equation; Y=-5.833343+17.86094X(X-the representative value of damage grade of Pineus armandicola).By taking into account of the differences of the volume, wood price, control cost and control effect on the basis of the regression equation, the dynamic model of the control threshold of the pest was formulated as: X_ET=C/(D×J×E)×100+5.833343/17.86094(C-control cost, D-checked volueme, J-wood price, E-control effect).This model provided the theoretical evidence for integrated control of the diseases and pests on Pinus armandii.