本文首先探討董仲舒思想的陰陽觀念在程序上是以元氣為根源而來有一氣之化為陰陽的表現，董仲舒尤其藉此論述太陽、少陽、少陰、太陰分佈為四時變化過程，並以此為宇宙規律的基本秩序性與實質意義。董仲舒五行觀念則有三種理路型態，一是成歲過程中相生與相剋的循環，二是以方位之「中」位觀念建立「土德」的輔助地位與核心作用的重要性，三是確認木火土金水做為五氣是各自相對獨立卻又是共同運行之作用、性質、活動、現象與理則，並且可以五行之氣與陰陽結合。而董仲舒據陰陽五行氣化所建立之論述，乃為人性實踐之目的而立論，即從陰陽五行降命為人性表現的可能性，藉此啟導有德的主政者朝向開發人性之善之禮樂教化為政治實踐之天命。

This essay aims to investigate the foundation of Dong Zhongshu’s conception of human nature and ritual in pollical practice by discussing his use and transformation of the established concepts of yin-yang and the five phases, along with their integration into the cosmology of Qi in his thought. Regarding yin-yang, Dong argues that the origin of the universe involves the transformation of primordial Qi into yin and yang. Dong argues that the distribution of taiyang, shaoyang, shaoyin, and taiyin as corresponding to the rotation of the four seasons, representing the fundamental order and substantive meaning of the universe’s laws.
Dong’s concept of the five phases relies on primary lines of reasoning: first, the cyclical process of mutual generation and mutual restraint during the seasonal transitions; second, the establishment of the“earth as virtue”in a central and supportive role, reflecting the idea“centrality”in directional cosmology; and third, the recognition that the five Qis - wood, fire, earth, metal, and water - are relatively independent but operate together through their functions, properties, activities, phenomena, and principles, while also combining with the Qi of yin and yang. Dong’s discourse on the transformation of yin-yang and the five phases serves the practice of cultivating human nature. Its purpose is to guide virtuous rulers to prioritize the development of human goodness as the central mission of political governance. Given the intrinsic value endowed by the Way of Heaven into human nature, the positive theoretical significance of Dong’s cosmology of Qi–based on yin-yang and the five phases - should be duly recognized.