Abstract: [Purpose/Significance] China has entered the aging society since 2000 and China's elderly population is increasing rapidly., The degree of aging is growing severely, and the pressure on social security and public services is increasing. During the "14th Five-Year Plan" period, the degree of aging in China will be from mild to moderate, the population structural contradiction centered on population aging is becoming increasingly prominent, and the demand structure of the elderly is changing from the survival-type to the development-type. In order to implement the national strategy and relevant national policies and regulations to actively respond to the aging population and fulfill the mission of public libraries, public libraries should further study how to better serve the elderly. [Method/Process] The paper conducts literature review of the current studies on public library services to the elderly. The main research methods in this field include questionnaire survey and case analysis. The research topics include study of the elderly, service, service system and service facility to the elderly. Among them, the research of service to elderly includes theme space and theme branch library construction, outreach service, health information service, reference service, user education and training, digital service, information literacy service, volunteer service and intergenerational service project. [Results/Conclusions] There are some problems in the existing research, such as a lack of standardization, the need to strengthen the scientific data collection method and a lack of in-depth research. In the future, efforts should be made to improve the norm of research and improve the data collection methods, such as paying attention to the rationality of sampling methods and the compatibility between the research methods and research questions, using in-depth interviews and other research methods, increasing in-depth case analysis, and comprehensively applying a variety of research methods. Efforts are needed to study the elderly group to effectively promote the match between the elderly service supply and user demand in public libraries. In order to adapt to the national conditions of aging in China and the characteristics of the elderly, efforts are needed to innovate service models from the aspects of service publicity and promotion, helping the elderly with digital intelligence, outreach service, intergenerational services, and social integration. There is also a need to evaluate the effectiveness of services to the elderly and develop the elderly service standards to provide guidelines for services for the elderly, and promote service experience. The construction of information resources adapted to the characteristics of the elderly population should be carried out to improve the level of service guarantee for the elderly.

Key words: public library, the elderly, library service, health informatics, research on information behavior