Medical assistance systems are an integral part of the health security system and they represent the integrity and adequacy of health risk protection. The overwhelming majority of developed countries have already es-tablished medical assistance systems to improve the accessibility of healthcare services and provide catastrophic pro-tection for families, especially for the poor. The paper conducts a comparative study of typical foreign medical assis-tance systems, where in the general method by which developed countries embed catastrophe protection mechanisms into public healthcare security systems and provide tilt protection to the needy is described. Medical assistance is pro-vided on a means-test basis and the development of private health insurance is encouraged to alleviate pressure on the public side. Corresponding implications for China are also warranted, including the provision of tilt protection to the needy, to re-define objects and standards of medical assistance, and enhance the coordination of different medical se-curity systems.