The academic characteristics in the Sung Dynasty focused mind nature researches and tried to realign humanity and rationaligation. Such national thoughts did not belong to Confucianism only. Researches on ”Lao-Zi” had gradually populeriged since the Northern Sung Dynasty. Many scholars had noted the ”Lao-Zi”. Sue Zhe (1039-1112) was an outstanding scholar in the Northern Sung Dynasty. He had interpreted the ”Lao-Zi” by thought of mind nature. Many current scholars neglected the thought of mind nature and theoretical framework when they researched ”Explaining Lao-Zi”. Therefore, the purpose of this essay try to understand the theoretical framework of ”Explaining Lao-Zi” based on many researches in ”Explaining Lao-Zi”.