In the study of forest growth and yield, and individual tree in a stand is used as the fundamental component for evaluating the effects of silvicultural treatments on tree characteristics as well as for making stand simulation models. Individual tree or surrounding density. This trend is appeared more clearly in the unthinned stand. In this study, relationship between growth of individual trees and density around them was analyzed by the use of the angle summation method (AS method), and then multiple regression equations including sizes of the center trees and surrounding density measures by the AS method were given for estimating diameter increment for the last years and the next few years of center trees.