Produced in the late period of Warring States, the complete structure of the Lunar System (the Yue-Lin) was positively presented in the 12 annals of Lu's Spring and Autumn (Lu Shi Chun Qiu). Increasingly developing with the progress of the calendar over the dynasties, the Lunar System also accumulated various cultural elements in all aspects from the progressive stages of the ancient civilization. In the Lunar System, all objects arranged according to time and space clearly manifested the relation with the ancient astronomy. Based on the concept of the five elements, the Lunar System within twelve months was constructed by the five directions, the four seasons and the twelve months. In my opinion, presenting the inheritance from the ancient astronomy, the Lunar System couldn't be simply supposed to be produced by the Yin-Yang School in the Pre-Qin period.