Objective: To understand the utilization of health services for middle-aged and elderly people in China, and compare the different factors affecting the utilization of outpatient and inpatient services. Methods: Based on the 2015 "China Health and Retirement Longitudinal Study" (CHARLS) data, a total of 12 974 participants were included. Thechi-square test was used for univariate analysis, and the logistic regression model was used for multivariate analysis. Results: The four-week prevalence rate of middle-aged and elderly people was 29.5%, the four-week consultation rate of middle-aged and elderly people was 20.2%, and 31.4% middle-aged and elderly patients did not visit hospital; The annual hospitalization rate of middle-aged and elderly people was 14.0%, and the annual hospitalization rate of middle-aged and elderly patients was 29.9%. The common influencing factors for the use of outpatient and inpatient services for middle-aged and elderly people included the prevalence of different chronic diseases, type of medical insurance, economic level, self-assessment of health status, whether having physical examination in the past two years. Gender had a significant impact on the use of outpatient services, but not to the use of inpatient services; Age had a significant impact on the use of inpatient services, but not to the use of outpatient services. Conclusion: Health status, economic level, medical insurance type and health awareness were the common influencing factors for the use of outpatient and inpatient services in middle-aged and elderly people, and gender and age were the influencing factors for the different utilization of outpatient and inpatient services. It was recommended to further increase the compensation level of the medical insurance system and reduce the disease burden. In addition, health education for middle-aged and elderly people should be strengthened to enhance their health awareness.