On the basis of analyzing the trend of river seasonalization in Haihe drainage basin, the article lays special stress on exploring how river seasonalization influences ground water and environment in the downstream plain. In the final analysis, we consider that there is close inter influencing and cause effect relation between river seasonalization and extra exploitation of ground water. Because of extra exploitation of ground water, river seasonalization has been increasingly serious. Conversely, temporal spatial distribution, replenishment and flow field of ground water have been profoundly affected by more and more serious river seasonalization. Meanwhile, a series of environmental and ecological problems have occurred, such as deprssion cone of ground water, land subsidence, seawater or saline water intrusion, declining of the river course function, deterioration of water quality, and so on. Currently, the problems have become important factors which restrict social and economical sustainable development, and have influenced the living conditions of human being. It is therefore, a pressing and long standing duty that water resource be reasonably exploited and ecological environment be effectively preserved.