Abstract: Growth heterosis of two and three years old Liriodendron chinense X L. tulipifera seedlings from different mating systems,three of ten to twelve years old forest stands in Hubei, Hunan and Jiangsu province,and twenty-two years old stands were investigated, respectively. All of the hybrids showed notably growth heterosis. and strong adaptive faculty. The stem analysis was studied on L. chinense and hybrid trees,indicating that the forms of these trees were straight and full. The heterosis was further shown from the curves of volume growth,mean annual increment and current annual increment. And hybrids got into a fast growing period earlier than L. chinense. Twenty-two years old L. chinense and hybrids were half-mature stands, they did not get into the fastest growth rate period. The results of physical mechanics of four types of plywood from hybrid trees indicated that this plywood accorded with the standard of grade I mechanical character.