Abstract: The structures of diameter-class,crown breadth and height of Tetraena mongolica population were studied.Based on the static life table,the dynamic law of T.mongolica population was described.The study showed that the individual tree distribution of T.mongolica with the variation of diameter class and height,and crown breadth were in single peak and reversed J-type respectively.With the increase of the population age class,the mortality qx and killing power kx increased but the surviving rate lx decreased.The survivorship curve belonged to Deevey Ⅰ. Based on Leslie matrix,the change of the number of individual trees was different in the different age class under the undisturbed condition and the population dynamic changed from declination type to growth type.