Abstract: Based on a review on the development of forest hydrological model,the theoretical base,types and characteristics of the physically based distributed model (PBDM) was presented.There are three types of forest hydrological models,i.e.,black box models,lumped models and PBDMs.The black box models were set up only according to input and output to the watershed.The structures of lumped models based on the hydrological processes in the watershed.Compared to the black box model and the lumped model,the PBDM has considered the spatial heterogeneity in the watershed and distinguished with different cells and flow pathways,therefore can express the hydrological processes in both spatial and chronological dimensions.PBDM can be served as a tool for a better prediction of the natural and anthropological impacts on the water resources and environment in a definite watershed for the purpose of making scientific decisions in the watershed management.The author suggested that landscape ecology could make a theoretical basis and GIS could give a technical support to the PBDM.The long puzzled problem of upscaling in forest hydrology can expect to be solved with the landscape ecology and GIS supported PBDM.