Soil nutrients and the amount of fertilizer under constant fertilization in irrigation silting soils were studied in 20 years. Fertilization and administration suggestion were indicated based on the study in irrigation silting soils. Four long2term experiment sites of irrigation silting soils were monitored in Xinjiang province from 1987 to 2006. The changes of soil nutrients were investigated. The relationship between soil nutrients and the amounts of fertilization application was analyzed on the four sites. The result showed that soil organic matter,nitrogen and phosphor contents increased under long2term fertilizer for 20 years. Soil organic matter,total nitrogen contents increased 6116 g/ kg,01083 g/ kg. Averaging increment is 0132 g/ kg per annum and 01004 g/ kg respectively.Moreover,the values of alkali hydrolyzed nitrogen and available phosphorus contents increased per year were 1198 mg/ kg and 319 mg/ kg. On the other hand, soil available potassium decreased 63 mg/ kg for the 20 years,the average annual reduction is 313 mg/ kg. The results indicated that It is an appropriate way to combine mineral fertilizer and application in this soil. it is suggested that increasing N and Kfer2 tilizers and controlling P fertilizer and reasonably adjusting fertilization ratio should be considered. Therefore,the fertility of irrigation silting soils and production capacity would be maintained or improved.