Since the outbreak of the Covid-19 pandemic, disputes over various contracts have emerged one after another, bringing the principle of change of circumstances back into focus in both academic and practical fields. Reviewing the historical development of this principle, from its preliminary formation in Roman law to its gradual clarification and institutionalization in modern private law systems, it is evident that the principle of changed of circumstances continues to evolve. However, different countries adopt varying approaches to addressing change of circumstances, leading to contradictions in the practical application of contracts. Therefore, this paper examines the development and practical judgments regarding the principle of changed of circumstances in countries belonging to the common law and civil law systems. It also analyzes the principle as reflected in international conventions and norms. Finally, the discussion returns to the impact of the Covid-19 pandemic on contracts, exploring the importance and feasibility of applying the principle of changed of circumstances in this context. The paper concludes with insights and recommendations, providing a reference for handling similar contractual issues in the future.
