Abstract: [Objective and Method]The present study investigated the effects of nitrogen application rate on the abscission rate of cotton buds and bolls,on the basis of the survey of the abscission rate of cotton buds and bolls at different growth period.[Result]The results showed that if nitrogen application rate was too small or too large, the abscission rate of cotton buds and bolls would be different and only appropriate level of nitrogen application rate was used,there was no occurrence of serious abscission rate of cotton buds and bolls.[Conclusion]When irrigation volume was 5 250 m~3/hm~2, total N-amount of was 380 kg/hm~2, basal fertilizer was 40;,the first top dressing was 15;, the second top-dressing was 23;, the third top dressing was 22;, the abscission rate of cotton buds and bolls was the smallest in Kuerle of southern Xinjiang.The top fertilization of nitrogen of 22; at the late flower bolling stage and full bolling stage,it can make the abscission rate of cotton buds and bolls be the smallest and cotton yield be the highest.