A two-year continuous experiment was conducted to evaluate the effects of different forms of nitrogen fertilizers on tree growth, yield, and quality of pear. Eight-year-old Cuiguan pear trees were treated with a single application of ammonium nitrate or urea and combined amino acids under equal nitrogen conditions. The results showed that compared with single application of urea, single application of ammonium nitrate treatment significantly increased SPAD value, the leaf area and weight of 100 leaves increased by 2.8%, 5.9% and 7.2%, respectively. Ammonium nitrate combined amino acids treatment significantly increased the fruit weight. Compared with single application of urea, single ammonium nitrate treatment significantly increased yield per plant, firmness of fruit and soluble sugar, an increasing trend was found on the content of soluble solids and titratable acidity. At 110 days after flowering, ammonium nitrate combined amino acids treatment significantly increased the growth of fructose, glucose and sucrose than single ammonium nitrate. Various sugars had different proportion in each period. Sorbitol was the most abundant sugar during 46 days after flowering, accounting for 69%–73% of the total sugar content, glucose and fructose had a quite proportion; with the fruit developed, fructose and sucrose content increased, but the proportion of sorbitol declined. Overall, Ammonium nitrate combined amino acids is most beneficial for improving pear growth and fruit quality.