Abstract: In 2015, China had more than 10 million Alzheimer's patients, which was the same number as the sum of the patients in all developed countries; dementia has become a serious social and public health problem in China. Due to the lack of effective treatment method on cognitive impairment and dementia disease, finding the risk factors has become the key issue for the prevention of the disease. With the rapid development of China's industrial economy, air pollution has become a major public health problem, and many studies have shown that air pollutants have a certain influence on cognitive function damage and dementia in the elderly. This paper reviews the studies on the relationship between air pollutants and cognitive impairment and dementia in the elderly for providing some new ideas on reducing the incidence of cognitive impairment and dementia.