The historical change in the concept of frailty has been observed from 1980s, and even now there are major two models of frailty, phenotype model and deficit accumulation model. Furthermore besides physical frailty, psychological frailty, which encompasses cognitive and mood components, and social frailty, which includes the lack of participation in social networks and perceived lack of contacts and support, have been proposed, although there is no consensus regarding the definition as well as criteria of these frailty. In super-aged society, Japan, from the viewpoint of healthy life expectancy, the concept of phenotype model of frailty is important.