Abstract: Drought-wet change is a kind of water environment in crop production process. To use compensative effect of crops, caused by supplying water after drought, is a new way for agricultural drought resistance and water saving. Based on the types of drought-wet change and the meaning of the compensative effect, the compensative effects in crops, different growing stages of crops, and physilogical capacity of the metabolism are studied. According to the experimental results of maize under moisture change of soil and atmosphere, the compensative soil drought effect on growth and water use efficiency by raising humidity of atmosphere was researched.