Abstract:In this paper, the relationship between tree population dynamics and stability in ravine tropical rain forest in Xishuangbanna has been studied. The result shows that the composition of tree populations is unstable and changes with time. The stability of structure and function (photosynthesis production) of the ravine tropical rain forest is maintained by a lot of tree popula-tions, and relative constancy of individuals in each layer. The ravine tropical rain forest has quite resistant to perturbation.