OBJECTIVE To provide insights for enhancing the supply assurance capability of drugs in shortage in China. METHODS By sorting out top-level design ideas for Japan’s stable supply system for pharmaceuticals， this study elaborates on its current policies for stabilizing drug supply. Policy suggestions were proposed for existing challenges in the supply of drugs in shortage in China. RESULTS & CONCLUSIONS To stabilize drug supply， Japan formulated a systematic 3-tier policy framework that ran through pre-prevention， early risk monitoring， and response mechanisms for supply problems. Pre-prevention measures included establishing a graded classification system for stable supply lists， strengthening government control over the drug production process， and implementing a continuous supply system and cessation reporting system for post-market drugs. Early risk monitoring included self-assessing risks in enterprises， disclosing information concerning supply assurance of enterprises， and providing enterprises with price protection and incentives measures. Response mechanisms for supply problems included establishing the mechanism of increasing production and coordinated supply in enterprises， opening fast-track review and approval channels for changes in raw materials， and establishing emergency systems of transferring drugs to supply. To balance supply assurance and strong regulation of drugs in shortage through refining the incentive and regulatory policies for them， it is recommended to refine the criteria for selecting drugs in shortage， strengthen the circulation of information， optimize price management methods， and clarify problem feedback and solving.