Abstract: Drought is the main factor restricting agriculture production. Development on water-saving agriculture is a necessary trend and is an ultimate measure for resolving agricultural water resource scarcity and ensuring agricultural persistence development. The study on coupling effect of water and fertilizer is an important part. This paper summarizes the status of study on coupling effect of water and fertilizer and introduces the mechanism and the effect mainly, including the effect of water apply to conversion, assimilation, metabolism of plant nutrition; the effect of nutrition apply to water utilization; biological effect; the effect of ecology; the physiological index of plant. Furthermore, it proposes the study fields needed to be strengthened in the future: the impacts of fertilization on the quality of agricultural products and ecological environment and the development of more universal models of water and fertilizer coupling.