In the paper, the basic situation and description of meridians are introduced on Zubi Shiyimai Jiujing (Moxibustion Classics of Eleven Meridians of Legs and Arms) and Yinyang Shiyimai Jiujing (Moxibustion Classic on Eleven Yin and Yang Meridians) unearthed from Mawangdui, Maishu (Book of Meridians) from Zhangjiashan, the lacquer figure from Shuangbaoshan, the lacquer figure as well as Maishu (Book of Meridians) unearthed from Laoguanshan. By analyzing the differences of the records of the aforementioned unearthed literature and the meridians described on the excavated lacquer figures in comparison with the "twelve meridians" in Huangdi Neijing (The Yellow Emperor 's Inner Classic), it is viewed that the development of meridian system, from "eleven meridians" to "twelve meridians", from "independent flowing line" to the circular motion channel as "endless cycling", is influenced by the symbolic model of image numerology of "6 for the Heaven and 5 for the Earth" and the law of the reciprocal change of yin and yang. The description of meridians by the medical scholars at the early eras are based on various kinds of practices, such as clinical diagnosis and treatment, qigong and daoyin. Hence, the construction of the knowledge system of meridians is affected by the symbol model of image numerology.