The elderly population all over the world is growing rapidly. Taiwan has entered an advanced age society in 2018. The growth rate of the elderly population is faster than we thought. The health issues associated with aging, such as the rapid population with mild cognitive impairment increasing, patient care may result in huge expenditures on national economy, society, family human and medical resources, and drugs; this article uses Cochrane library, PubMed (Medline), UpToDate, Google scholar as the database from the perspective of literature review with keywords: cognitive dysfunction, physical fitness, exercise prescription intervention, quality of life, etc. Search for 12 related documents on physical activity and cognitive function, neuroendocrine, molecular biology, etc.; including: case-control studies, systematic reviews, integrate analytical research and randomized clinical controlled trials to explore the effects of physical activity intervention and the fitness of the elderly in the epidemiology of dementia, prevention of cognitive decline, improvement of cognitive function, and improvement of quality of life. To further exercise prescription recommendations for physical fitness to improve cognitive function and quality of life. Understand which types of exercise intervention are positively helpful to improve the quality of life of patients with mild cognitive impairment and dementia; hope that the results of the article can be used as a reference for domestic health promotion plans, providing future care for the elderly with cognitive dysfunction and dementia prevention and treatment. Ideal physical fitness guidelines and exercise prescriptions in Taiwan.