Abstract: 【Objective】 To explore the effect of fulvic acid on grape and its optimum application rate. 【Methods】 Four-year-old 'Zhengyan Seedless' grape was taken as a test material, 0, 2.5, 5, 11, 33 and 100 g/plant fulvic acid were applied to the rhizosphere of grape at flowering stage, young fruit stage, coloring stage and fruit enlargement stage. 【Results】 The content of organic matter, nitrate nitrogen, ammonia nitrogen, available phosphorus and available potassium in soil was significantly increased by applying fulvic acid compared with that without fulvic acid application, which increased the L^* value, color index, sugar-acid ratio, VC content, fruit hardness and grape yield. The results of principal component analysis showed that 33 g/plant (0.33 g/L) were the most effective in improving soil nutrient, grape fruit quality and grape yield among the 6 treatments. 【Conclusion】 The fulvic acid can increase the content of nitrate nitrogen, ammonia nitrogen, available phosphorus, and available potassium in vineyard soil, promote the absorption of mineral nutrients by grape roots, increase the content of N, P, and K in leaves, synthesize and output more assimilation compounds, thus improving grape quality and increasing its yield. Among six groups, the physiological index of leaves was best when the amount of fulvic acid was 33 g/plant. It provides a theoretical reference for the reasonable application of fulvic acid fertilizer into 'Zhengyan Seedless' grape.