In Germany, after several heated debates care insurance was established in 1994. As a fifth branch of Bismarck's compulsory social-insurance systems, care-insurance has an important status in German social history. This paper seeks to explore why the need of care in German social structure is treated as a collective social risk and why members of society are protected against such risk through the social insurance model. The principles and schemes of care-insurance in Germany not only maintain the inter-consistency and stability of traditional German social-insurance systems but also adapt oneself to the change of social structure and develop a couple of innovations. The backgrounds for establishing German care-insurance are the same as Taiwan that confront with the ageing populations, changes of family form and burdens of social expenditure etc. Therefore, the German care-insurance experience is a good reference for the plan of relative social policies in Taiwan.