Abstract: Losing a certain number of one-year-old needles will have a significant effect on the height growth of Pinus tabulaeformis and the length of needles in the following year:the greater the loss,the more serious the effect. After two years,they will return to the normal status although still be different in height growth. If the losing is a small number of two-to-three-year-old needle,the pines have compensation and super-compensation effect,but if one-year-old needle,they have not. In the years when the pine caterpillar burst out and 95% of the one-to-two-year-old needles are lost,the pines will return to normal status in three years if the site situations are good and they will not if the site situations are poor,for example,a dry southern slope. So,in the control of pine caterpillar,making the widest possibility to reduce the loss of one-year-old needles is a key to ensure the normal growth of pine trees.