 This summary and review dealt with the history of forest hydrology and catchment research． Most results of the catchment experiments showed that forest clearing would increase the water yield but the impacts of the forest vegetation on water yield were complex，which depen ded on many factors such as topography climate， soil catchment area forest type， management and so on． It is impossible to extrapolate the result from one area to another or from one scale to another because there are many differences between them．A developing trend to study are the combination of data from a number of catchments that have different characteristics and the application of new measurring technics and approaches．