Abstract: 【Objective】 To clarify the dynamic changes of fruit quality of three yellow-green apple varieties Golden delicious, Harlikar and Ruixue during fruit ripening and then determine the optimal harvest time of the three varieties. 【Methods】 The starch staining patterns of three varieties were constructed, soluble solids were determined, titrable acids were determined, and sugar components and acid components were determined by liquid chromatography. 【Results】 With the improvement of fruit maturity, fruit weight, fruit shape index, soluble solids content, starch index and sugar content of the three yellow-green apple varieties showed an upward trend, while fruit firmness, titratable acid content, VC content and acid fraction decreased with the extension of harvest time. During ripening, starch index was negatively correlated with fruit hardness, titratable acid and VC, and positively correlated with single fruit weight and soluble solids. 【Conclusion】 It has been concluded that the harvest periods I,II and III are the suitable harvest periods for the three varieties, and the starch staining grade is 4-6 in this harvest period. For Golden delicious,the time of apple dyeing grade 4, 5 and 6 was 147, 153 and 160 days after full bloom, respectively. The dyeing grade of Harlikar reached 4,5 and 6 at 173, 180 and 187 days after full bloom, respectively. The time when the dyeing grade of Ruixue reached 4,5 and 6 was 187, 193 and 200 days after full bloom, respectively.