The medical and health related expenditures related to the aging is a huge burden on the country and the society. The geriatrics gradually becomes a hot spot in the clinical medicine. The core problem in the gerontology and the geriatrics is the senescence, along with related issues. But, the senescence starts actually as early as just after the human sexual maturity. Geriatrics deals with the secondary stage of senescence. If the assessment and the intervention of senescence-related issues can be carried out at a younger age, the senescence process will be delayed, the healthy life span will be extended, and the burden of the aging can be reduced. At the same time, the rapid growth of the elderly chronic diseases, such as the hypertension, the coronary heart disease and the diabetes, happens often in the middle-aged stage. Only by strengthening the comprehensive prevention and control of these diseases as early as possible can we control the progress and complications of these diseases in the long run and effectively reduce the burden of the whole society. Therefore, we might call the population of 45~59 years old the sub-elderly group. For this part of the population, it is important to adopt the method of the comprehensive geriatric assessment, to establish a sub-elderly health evaluation system, and to carry out systematic interventions.