Abstract: The water sciences deal with original water that occur in the nature as object and investigate their static distribution and dynamic variation of physical, chemical and biological processes, the mode of motion and the law of variation of the water in the hydrosphere. In the water sciences study there are also involved the interrelations and interactions between hydrosphere and atmosphere, hydrosphere and lithosphere, hydrosphere and biosphere, water and other components in the environment, water and human society. The water sciences in their progress should adhere to the principle of integrating cognition with practice, cooperating their property of natural science with that of applied sciences so that the relationship between humanity and water as well as nature may be treated at more reasonable and effective level.