Abstract: This paper deals more systematically with the application of fractal theory in many aspects to hydrology and water resources,including the structure of river network,the topography of basin,the surface geometry of river bed,the distribution of rainfall in time and space,the variation of flood in time and space,the process of runoff,the movement of ground water and infiltration.The characteristics which occur in the practice of the application of the fractal theory to hydrology and water resources shows the activity thinking and the creation in methodology for hydrology.Attention should be paid to the verification of the reasonable basis for such application based on a great deal of data.