Abstract: 【Objective】 Phosphorus and potassium fertilizers are important elements for grape growth and development, which have an important effect on the whole process of grape growth and development as well as the quality and yield of grape fruit.The objective of this study is to increase understanding of the different amounts of phosphate fertilizer and potassium fertilizer on fruit quality and yield of Frey seedless grape under protected culture during fruit expanding and coloring period. 【Method】 Different amounts of phosphorus and potassium were applied under fixed nitrogen fertilizer application. 【Result】 The results showed that the grape plant panicle weight and yield were highest when the P₂O₅ content was 14.6 kg/667 m² and the potassium application amount was 15.08 kg/667 m² in the local Frey seedless grape under protected culture during the fruit expanding and coloring period. And sugar and acid ratio, hardness and fruit coloring coefficient were better than those of the control and other treatments. The root system of grape was mainly distributed in the soil layer of 20-40 cm. 【Conclusion】 It is suggested that the amount of P₂O₅ content should be 14.6 kg/667 m² and the potassium application amount was 15.08 kg/667 m² in the local Flame seedless grape under protected culture during the fruit expanding and coloring period and the fertilization depth should be at the 20-40 cm soil layer.