Hydrology is derived from Geography as its branch and mainly studies the hydrological regimes of water bodies on land of the Earth. The establishment of water balance and circulation of water conceptions of is a significant progress in the formation of hydrology. The rising of hydraulic engineering demands hydrology to make not only the modifications, hut also the quantitative analysis and calculation of the hydrological phenomena. The Engineering Hydrology rose at the historical moment, then developed rapidly and occupies a principal position in hydrology, rersulting in the advance of hydrometric techniques. The Engineering Hydrology is the subject of technical sciences, and together with the Geographical Hydrology, enrichs the content of hydrological sciences. Consequently, the social develoment spurs the increase of water demands and the exploitation and utilization of water resources in a large scale, and the connotation of hydrological work for rational management and use of water resources, as well as for the safe and economic operation of water resources projects should adapt to this fact. The breakthrough of modern techniques promotes the hydrology to a new Stage, the stage of Wa ter Resources Hydrology. This stage is characterized by dealing with the necessity for water resources system analysis and rational management. The hydrology involves not only the problems of natural sciences and technical sciences, but also those of the, social Sciences. In this paper the characteristics of Water Resources Hydrology and the features of this new stage are discussed. The recent tendency of intermational hydrological scientific activities can prove this transformation evidently.