Abstract: Taking 17-year-old Acer truncatum stand as reserch object, effects of exogenous kinetin 50 mg/L and 0.5 mg/L 2, 4−epibrassinolide on phenotypic traits, seed yield and quality of A. truncatum were analyzed. The results indicated that the seed width and thickness increased significantly after foliar application of 2, 4−epibrassinolide, concentrations of soluble sugar, protein, oil and nervonic acid were significantly higher than CK; spraying kinetin induced significant increase in contents of soluble sugar, protein, oil and nervonic acid and hundred-grain weight and single branch yield were significantly higher than CK. According to analysis of various indicators, promoting effect of 2, 4−epibrassinolide on A. truncatum was slightly better than kinetin.