Abstract: The effects of nitrogen application on leaf area index, dry matter accumulation and yield of summer soybean were studied in Yining County of Xinjiang from 2015 to 2016. The results showed that the leaf area index, dry matter accumulation and yield of summer soybean increased first and then decreased with the increase of nitrogen application rates, and all were the highest at nitrogen application rate of 150 kg/hm2 (N1), followed by 300 kg/hm2 (N2). With the advancement of growth process, the leaf area index of summer soybean increased first and then decreased, reaching its peak value at full pod stage, and under N1 treatment, the leaf area index was 5.59, which was 49.07% and 13.39% higher than that of N0 and N2, respectively. Nitrogen application increased the maximum accumulation rate and duration of rapid growth of summer soybean dry matter. In the two years, the post-anthesis dry matter accumulation under N1 treatment was the highest of 15.70 g/plant, which was 40.32% higher than that of N0. The translocation and contribution of nitrogen treatment were significantly higher than that of non-nitrogen treatment, and N1 was the highest in the two years. The translocation was 53.33% and 12.47% higher than that of N0 and N2 treatment, respectively, and the contribution rate was 17.97% and 4.23% higher than that of N0 and N2 treatment, respectively. N1 had the highest yield of 2929.56 kg/hm2 by two years average, which was 29.42%, 6.53% higher than that of N0, N2, respectively, reaching the significant difference level.