The informatization is the only way of history development. The Water Resources informatization has very important status and action by way of an important industry of national economy. The Water Resources informatization is important feature of Water Resources modernization. To research essence of the Water Resources informatization, can get the model of the Water Resources informatization system. Every layer of the Water Resources informatization system needs to use a lot of information technology. The information service platform constructed by the web service can solve integration of these information technologies in the Water Resources informatization, provide data and application system share.