The increment of the proportion of elderly population has been very rapid not only in the developed country but also in South Korea during the second half of the 20th century. This demographic change attracts an interest in the field of the Gerontology and Geriatric Medicine and also need for the specialists in this field has been increased. There are different terminologies which are related each others; Gerontology which is the scientific study of the problems of aging in all their aspects- clinical, biological, historical, and sociological and Geriatrics which is the branch of medicine which treats all problems peculiars to old age and the aging, including the clinical problems of senescence and senility. The elderly who is the object of geriatrics, usually is defined by age (for example, over 65) or by physical condition and disability. The characteristics of elderly comparing with young are vague presenting symptoms and chronicity and progressively deteriorating. Geriatrician has an ability to be a comprehensive and know the importance of multidisciplinary approach. By far, the assessment the function of the elderly patient are an important tool for diagnosis and planning the treatment. The one of the most important goal of elderly is to keep the function to live independently as long as possible. (J Korean Acad of Rehab Med 2002; 26: 367-369)