记R=F_2+uF_2+u~2F_2,定义了环R上码字的李重量分布的概念,构造了从R~n到F_2~(3n)的Gray映射φ.通过对环R上线性码及其对偶码生成矩阵的研究,证明了环R上线性码及其对偶码的Gray象是F_2上的对偶码.利用域F_2上线性码及其对偶码的重量分布关系,得到了环R上线性码及其对偶码关于李重量分布的MacWilliams恒等式. The concept of the weight distribution of the codewords on the ring R is defined, and the Gray mapping φ from R ~ n to F_2 ~ (3n) is constructed. By means of the linear codes of R ~ F_2 + uF_2 + u ~ 2F_2, The research of its dual code generation matrix proves that the gray image of the linear code and its dual code on the ring R is the dual code on F_2.Using the weight distribution of the linear code on the field F_2 and its dual code, The MacWilliams Identities of Li Weight Distributions and Their Dual Codes.