The experiments were carried out with the self-mating progenies derived from ‘Qinshu No.1’ sweet potato and twelve quantitative characters were determined i.e. the number of vine branches (x1), the longest length of branch (x2), the length of all branches (x3), the internode length (x4), the thickness of branch (x5), the area of leaf (x6), the weight of green leaves of single plant (x7), the weight of branches leaves (x8), the root tuber number of single plant (x9), the root tuber weight of single sweet potato (x10), T/R valve (x11) and root tuber weightof single plant (y). The results showed that the weight of green leaves of single plant greatly influenced root tuber weight of single plant, the root tuber number of single plant and root tuber weight of single sweet potato were secondly. So in high yield breeding, it should be considered all the seven traits, not only the weight of green leaves of single plant, the root tuber number of single plant, the root tuber weight of single sweet potato, but also T/R valve, the number of vine branches, the area of leaf, the thickness of branch.