Abstract: To explore the mechanism of high WUE in intercropping system,the experiment of intercropped and monocropped models of maize and cabbage was conducted in dryland agriculture areas in Shouyang of Shanxi province.The results indicated that （1）water use by maize and cabbage intercrops in the growing season was lower than monocropped maize and was higher than monocropped cabbage,which resulted in higher soil moisture in intercropped models than maize monoculture and lower than cabbage monoculture during the middle and later growing stage For the intercropped models,as the rows of maize were decreased (or the rows of cabbage were increased),its soil moisture was increased gradually. （2）The soil water contours were the deppest in maize monoculture,and the shallowest in cabbage mowoculture during the middle and later growing stage Water use intensity of the monocropped maize was higher than the monocropped cabbage before mid August and was lower afterwards Intercropped models of maize and cabbage formed temporal and spatial complementary on using water,so it improved water use efficiency. （3）Yield of maize was increased in intercropping.The growing of cabbage in intercropped models was shaded by maize to different degrees,but the effect was weaker as the rows of cabbage was increased,even was disappeared.When the cabbage rows in intercropped models were more than four (one time than maize height),yield,output value and water use efficiency of the intercropped maize and cabbage was higher than the monocropped maize and cabbage respectively. The conclusion was that when the cabbage rows in intercropped models were more one time than maize height,the intercropped models were reasonable and better.

Key words: Maize, Cabbage, Intercropping, Water use, Yield, Water use efficiency