OBJECTIVE: To introduce diagram of Nine-mansions in which another diagram named Xian-Tu is nested together with the mathematical knowledge hidden in them. METHODS: Exploring with algebraic method the diagram of Nine-mansions and diagram of Xian-Tu nested in it and comparing the diagrams with the eight-pointed-star veins. It widely exists in the Neolithic Age's antiques found in China. RESULTS: The golden rectangle and golden spiral were found hidden in the diagrams and they show close relationship with eight-pointed-star veins. CONCLUSION: The mathematical knowledge does exists in the diagram of Nine-mansions and Xian-Tu, which may mean something for Traditional Chinese Medicine (TCM) for its discourse on Nine-mansions and Eight-winds obviously employed the diagram of Nine-mansions for its medical purpose.