Abstract:The ecological functions of forests,such as hydrological regulation,soil protection,peak discharge reduction,are summarized based on the analysis of eco-hydrological processes and of the forest ecosystem structure.The current worldwide hot topic about the water yield reduction caused by afforestation is also discussed in this paper.It is suggested that the benefits of forest should be evaluated by a integrated approach.However,the basic research of forest eco-hydrology should be strengthened for intensifying the scientific and technical basis of decision making in forestry development and forest management,as well as for increasing the decision making ability in the integrated management of forest vegetation,water resource and regional development.