Abstract: Low yield of Xinyi(the flower bud of Magnolia)has become the main factor to hinder the development of Xinyi industry. Focused on the yield,this paper analyzes the genetic parameters of 15 characters and selective index of yield for 7 varieties of Flos Magnolia. Results of analysis show that the heretability of Y(Xinyi yield)is 0.69,genetic variation 42.9%, and genetic gain by direct selection 60.3%. Mf(mass of hundred floses)and Nf(flos number per branch),whose heretabilities are 0.73 and 0.65,genetic variations 43.7% and 82%,correlative selective efficiencies 96.1% and 96.2% respectively,are two main characters for the selection of Y, but the heretability of Nt(total number of flos)only 0.24,and the efficiency of correlative selection for Y only 1%,may not be regared as the selective character. Leaf characters have significant genetic correlation with Y,in which A1(area per leaf)and W1(width of leaf),whose selective efficiencies for Y 96.1% and 96.2% respectively,are two indirect characters for the selection of Y. Moreover,the selective index of yield,made of Nf, Mf and A1,has response(3.859 kg per tree)and genetic gain(72.1%),increase the efficiency 19.5% than by direct selection. Based on the index,the sequence of different varieties is ‘Axilliflora’,‘Sijihua’,‘Tongchui’,‘Ovata’,‘Biondii’,‘Xiaotao’and ‘Naizui’.