The incidence of dementia has been rising exponentially and became one of the main public health problems. Although therapeutic agents toward improvement of cognitive and behavioral symptoms of dementia are present, there are no available disease-modifying treatments for any of the dementia yet. However, the researchers are working on the development of curative pharmacological agents these days. The thesis contains brief explanation of pathophysiology of most common types of dementia (Alzheimer disease, Vascular dementia, frontotemporal dementia and Lewy body dementia). Also, currently used therapeutic agents for each dementia and drugs on clinical trials are discussed as well.