| Centennial Seedless was used to study the effects of fertilizer ratio on the growth and absorption, distribution and utilization of15N-ammonium sulfate of grape under water stress. Three different water treatment levels（75%～80% FC、55％～60% FC、40％～45% FC） and three kinds of fertilizer ratio（N∶P∶K=2∶1∶3、N∶P∶K=2∶1∶5、N∶P∶K=2∶5∶3）, total 9 treatments were designed in the experiment. The results show that: there are significant differences among the treatments of different water and fertilization ratio on the shoot roughness, the grape leaves area and the chlorophyll content of grape leaves. the treatment of 55%～60% of field capacity, fertilizer ratio of N∶P∶K=2∶5∶3 can effectively increase the shoot roughness and the grape leaves area, suit for the growth of Centennial Seedless grape. the treatment of 40%～45% of field capacity, fertilizer ratio of N∶P∶K=2∶1∶3 can increase the chlorophyll content of grape leaves. The treatment of 55%～60% of field capacity, fertilizer ratio of N∶P∶K=2∶5∶3 can effectively increase photosynthetic rate and decrease transpiration rate. The Ndff% order and partition rule of 15N of various tree organs are not changed under different water and fertilization ratio treatments, while the Ndff% and partition ratios of15N of same organ are different, the15N requisition ability of grape saplings at the mild stress level was best. The15N distribution rates and use efficiencies of various tree organs in different treatments were difference. The15N distribution rates and use efficiencies of roots were significantly higher than other organs, up to 43.37% and 11.17%, new shoot and trunk were second, and leaf was minimal. Under mild stress level, increasing phosphorus and potassium fertilizer can lead to the increase of nitrogen fertilizer use efficiencies. In summary, the treatments of 55%～60% of field capacity, fertilizer ratio of N∶P∶K=2∶5∶3 were optimal，which is recommended in the fertilization and irrigation in grape production and cultivation． |