Abstract: As woody energy plant, Xanthoceras sorbifolia Bunge’s seed yield is the main factor restricts its exploiture. 26 characters about plant shape, leaves, fruits, seeds, yield and oil content of 357 Xanthoceras sorbifolia Bunge plants were analyzed by using correlation, multiple regression and path analysis. The main factors restrict seed yield were found. The result showed that seed yield was significantly positively correlated with basal diameter, crown width, leaf length, leaf area, fruit length, fruit width, seed number per fruit, fruit weight and fruit number. It was positively correlated with pericarp thickness, carpel number, seed length, seed width and weight of 100 fruits, and was negatively correlated with height below the first tress. Fruit weight, seed ratio, number of fruit, seed number per fruit and seed width were the main traits affected plant seed yield. Fruit weight, fruit number and seed ratio had more contribution to seed yield, and these characters were the main characters to considerate when choose high seed yield plant.