Abstract: 【Objective】 To explore the dynamic changes of sugar and acid content during the ripening process of grapes. 【Methods】 ight varieties of grape were used as research materials which were cultivated in northeast of China. Based on high performance liquid chromatography (HPLC), the components and content changes of sugar and acid were measured during the different process stages of grapes. 【Results】 The average total sugar content of the 8 grape varieties in mature grapes was 182.74 mg/g FW, among which, the total sugar content of 'Bei Binghong' was the highest (236.82 mg/g FW) and the 'Red Globe' was the lowest (139.82 mg/g FW). Glucose and fructose were the main soluble sugars with a content of about 1.1:1, which accumulated gradually with the process stages of grapes. The average content of organic acids of the 8 grape varieties in mature grapes was 7.64 mg/g FW, mainly tartaric and malic acid which accounted for more than 87.79% of the total acid. Among them, the content of organic acids of 'Shuang Hong' was the highest (12.69 mg/g FW) and the 'Victoria' was the lowest (3.96 mg/g FW). Except that the Euramerican hybrid of "Fujiminori" and "Takatsuma" contained malic acid as main organic acid (52.60% and 53.77%), the other grape varieties contained tartaric acid as main organic acid (47.39%~66.16%). 【Conclusion】 The major soluble sugar in grape fruits is glucose and fructose, and total sugar content increases with the ripening process of grapes. The major organic acid was tartaric acid and malic acid, and total acid content increase first and then decrease with the ripening process of grapes. The order of the rapid accumulation of sugar and the rapid decomposition of organic acids in the grapes of each variety correspond to the length at the mature period, while the time required for the rapid accumulation of sugar and the rapid decomposition of organic acids have no direct relevance to the length of the growth and development cycle of each variety.