The moonthly ordinances (Yueling) is an important style of chronography documents in ancient China. which can be divided into comprehensive moonthly ordinances and agricultural moonthly ordinances according 1o its content. Since Simin Yueling of the Eastern Han Dynastys, a series of comprehensive monthly ordinances, such as Tang Yueling and the agricultural monthly ordinances, such as Sishi Zuanyao, Yangyu Yueling and Nong pu Bianlan, have incorporated the system of the 24 Solar Terms and taken them as important monthly points. The combination of the 24 Solar Terms with the moonthly ordinances played a practical and empirical role in arranging rituals, predicting westher and harvest, and guiding agricultural production. The 24 Solar Terms have shown a tendeney to change from focusing on farming to serving rituals and divination, and then to focusing on agricultural production and life techniques.