For precipitation increase by 10% during GPw, yield decreased for winter wheat in Zone I, Zone II and Zone V of northern China by 0.4%, 0.4% and 0.2%, respectively; and in Zone III and Zone VIII of southern China by 1.9%, and 1.7%, respectively. In northwestern China, spring wheat yield decreased in Zone IV and Zone VII by 0.6%,however increased in Zone VI by 1.3% (Fig. 5).