Abstract: Taking Korla fragrant pear grafted by the Ninth Regiment of Alar City in Xinjiang for five years as experimental materials,the effects of different nitrogen application levels (N1(150kg·hm^-2),N2 (225 kg·hm^-2),N3 (300 kg·hm^-2),N4 (375 kg·hm^-2),and N5(450kg·hm^-2))on soil nitrogen nutrients and total nitrogen content of plant leaves during the growth period of Korla fragrant pear orchard were studied through randomized block design,in order to explore the appropriate nitrogen application amount in pear orchard.The results showed that the effect of increasing N fertilizer application on soil nutrient content of 0-40cm soil layer was more significant,and the content of nitrate nitrogen,ammonium nitrogen and alkaline nitrogen in 0-40cm soil layer showed a general trend of‘increase-decrease-increase’;with the increase of N fertilizer application,the content of nitrate nitrogen,ammonium nitrogen and alkaline nitrogen in each treatment changed as follows,0-20cm＞20-40cm＞40-60cm.With the increase of nitrogen fertilizer application,the total nitrogen content of pear leaves showed an‘increasing-decreasing’trend,and the total nitrogen content of each treatment showed that the leaves of current year branches＞leaves of multi-year branches.The content of stone cells,soluble sugar and vitamin C content showed an increasing trend with the increase of N fertilization,and then decreased.N3and N4treatments had higher nutrient content and better fruit quality.