The growing process of winter wheat is simulated by CERES-wheat model assuming the daily temperature variation to be-1℃, 0℃, 1℃, 2℃and daily precipitation change to be - 20% ,-10%,-5%,0,5%,10%,20% respectively. The case study site is of zhenjiang,Jiang-su Province, which locates in the middle east of China. The simulation results show that the impact of temperature variation on winter wheat is stronger than that of precipitation change. Warming climate can speed up the development rate and shorten the phenological period. In ge-neral,the adverse effect of climatic change on grain yield is greater than that of its beneficial effect, especially when the climatic cooling and drying. Both the temperture increase and precipitation decrease can reduce the plant extractable soil water content.