In 2012,a lacquer figure was unearthed from the Han dynasty tomb (188 BC-87 BC) at Chengdu Laoguan-shan.The lines intaglioed on the Laoguan mountain lacquer figure were similar to the meridians.Objective:To investigate the relationship between the lines on this Laoguanshan lacquer figure and the regular meridians so as to explore the development of meridian system in ancient China.Methods:Based on collecting the photos of the Laoguan mountain lacquer figure and the representative acupuncture classics,the double evidence method (combining the unearthed relics / literature and ex-tant literature) was performed to investigate the relationship between the lines on this Laoguanshan lac-quer figure and the regular meridians.Furthermore,the development of regular meridians theory was analyzed from the number,distribution,direction and branches.Results:The routes of the 28 longitudinal white lines on the Laoguan mountain lacquer figure are similar to the regular meridians in the ancient literature including Huángdì Nèijīng (《黄帝内经》 Yellow Emperor\'s Inner Classic).The number,distribution and branches of the meridians intaglioed on the Laoguanshan lacquer figure suggested the evolution of the regular-meridian system from the eleven-meridian system to the twelve-meridian system.Conclusions:The meridian system of Laoguanshan lacquer figure was a link connecting the preceding and the following.The Laoguanshan lacquer figure played an important role in the development of the early meridian theory.