Water resource shortage is becoming a major problem in the North China Plain, especially in groundwater resource because groundwater table is persistently declining. A Soil-Water-Balance approach was used to simulate crop evapotranspiration (ET) and soil water recharge (D) at Luancheng Agro-ecosystem Stationin the North China Plain, and grain yield (GY) and water use efficiency (WUE) for wheat (Triticum aestivum L.) and maize (Zea mays L.) were investigated under different irrigation schedules. Results indicate that ground-water mining of about 200 mm/a from the rapidly depleting aquifer system supplies the deficit under normal soil water condition in winter wheat season. Reversing ground-water declines due to irrigation will mean either reducing the irrigated area, reducing grain yields, or both, which suggests that it is suitable to reduce wheat-cropped areas. Although severe SWD decreases both ET and GY of wheat and maize, slight SWD for winter wheat during a stage from green turn to grain-filling stage did not evidently reduce GY. SWD, severe or slight, all significantly reduced ET, which mainly depended on the different irrigation amounts. Thus, it is possible to reduce ET somewhat instead of reducing GY. In a long way, in order to keep sustainable ground-water mining, the cropped area of winter wheat needs to decrease, while it is very crucial to increase the area of economic crops with low water consumption.