Many political scientists believe that ontology is essential to political philosophy. Although it is arguable that the interwoven effect of political thoughts - Confucianism and Buddhism - served as the prominent factors for China to attain the golden age of cosmopolitan prosperity for hundreds of years, the ontological explanation is essential in light to discover the underlying political contributions that granted Tang China to become the most desired metropolitan in the primeval history. This paper examines Tang’s foreign relations structure as an ancient imperial capital by applying the conceptual framework of Confucianism and Buddhism as the essential political virtues behind the governance. To understand the causal effect of the political thoughts over Tang’s foreign relations system, I put emphasis on the historical development on the ideas of Buddhism and Confucianism in Tang dynasty, the intellectual adaptations of Buddhism and Confucianism by the emperors and senior officials during the eras of Emperor Tang Taizong (Li Shimin李世民) (Zhenguan貞觀年 627-649) and Empress Consort Wu (Wu Zetian武則天) (Tianshou天授年 690-705), whom thus transformed the core values of the two teachings into actuality, and the political implications of the infiltrated belief systems of its foreign policies toward Turkic and Tibetan regimes. The goal of this research is to elevate the study of Chinese idealism, to emphasize the essential role of political philosophies which influence the nation’s governance structure for centuries, and to engage with the conversation that links the conventional wisdom amongst the international scholarship across the East and West. Ultimately, the implications of this study show that regardless how China transforms through the evolution of time, its political mentality and historical legacy transcendence well into the contemporary era.