Despite recent development in the study of the First World War (WWI), research on China’s experiences in WWI is still largely limited to the discussion of several discrete topics: the war participation debate, the Chinese Labour Corps, and the May Fourth Movement. This dissertation argues that the First World War was a transformative event that significantly shaped the constitutional trajectory of the nascent Republic of China. The outbreak of the First World War shifted the balance- of-power in East Asia, which had important bearings on China’s domestic politics. The retreat of Western financial and diplomatic support as well as Japan’s increasing leverage in China created considerable obstacles to the Beijing government’s centralisation project and formed the international context of subsequent constitutional crises. China’s war participation debate went far beyond the realm of foreign affairs. It became an arena for competing proposals about how to reorganise national politics in a fragmented political landscape. China was also deeply influenced by and actively participated in the making of the WWI Zeitgeist. The shifting intellectual and social trends during the period provided momentum for new ways of political participation in Chinese politics, influencing both the central government and its challengers. By portraying the close interaction between international and domestic developments, this dissertation tries to highlight the international context of the failure of the constitutional experiments under the Beijing government, something that has often been overlooked in the revolutionary narrative of modern Chinese history. Apart from providing a new perspective from which to revisit early Republican history, the depiction of China’s encounter with WWI can also serve as a case to enrich our understanding of the First World War as a truly global war that shaped the modern world.