Abstract: 【Objective】 To compare the differences in the sugar and acid content of Korla fragrant pears during the growth period of the three regions: KorlaAksu, Xinjiang and Jiuquan, Gansu, and explore the quality changes of the fruit during the growth period so as to provide references for quality control and reasonable harvest of fragrant pears. 【Method】 Korla fragrant pear fruits 100-150 d after flowering (secondary expansion and maturity) were collected, and direct titration was used to determine reducing sugar and total acid content, and high performance liquid chromatography to determine fructose, glucose and sucrose, and the contents of five organic acids: malic acid, succinic acid, citric acid, tartaric acid, and fumaric acid, and finally their changes with fruit growth were explored. 【Results】 As the fruits continued to grow and mature, reducing sugar, fructose, and glucose showed a gradual increase trend.The fragrant pears in Korla and Aksu reached the maximum value of fructose at 140 d after flowering (150 d in Jiuquan); The glucose content of pears reached the maximum 120 d after flowering (130 d in Aksu and Jiuquan); the main organic acids such as malic acid, citric acid, and tartaric acid showed a gradual decline, and the content of malic acid and tartaric acid reached the minimum 140 d after flowering (150 d in Jiuquan); the sugar-acid ratio increased from 29 at 100 days after flowering to 57 at 140 days.The contents of fructose, glucose, and sucrose in ripe Korla fragrant pear fruits were 51.1, 51.0 and 0.83 mg/g; the contents of malic acid, citric acid, succinic acid, tartaric acid, and fumaric acid were 0.68, 0.20, 0.17, 0.15 and 0.04 mg/g, respectively. 【Conclusion】 The sugars in fragrant pear fruits are mainly fructose and glucose, which account for 99% of the three sugars.Organic acids are mainly malic acid, citric acid, succinic acid and tartaric acid, the four of which account for 97% of the five organic acids.The ratio of sugar to acid reached the best ratio 140 days after flowering.It is recommended that the fragrant pears in Korla and Aksu should be harvested 140 days after flowering, and the fragrant pears in Jiuquan CityGansu should be harvested 150 days after flowering.