Comprehensive geriatric assessment（CGA） is one of the most important part of geriatrics, which is a multidisciplinary diagnosis and treatment process that identifies medical, psychosocial, and functional limitations of a frail older person in order to develop a coordinated plan to maximize overall health with aging. It has been implemented in all the process of the continuous care of the elderly. This article introduced the application and the efficacy of CGA in the practice of acute and sub-acute elderly care, geriatric consultation, transitional care, outpatient and home-based elderly care. As a whole, CGA and followed intervention produce a better health outcome for the older patient and reduce the burden of the society.