OBJECTIVE： To provide reference for the further promotion of “New Medical Reform” and the further implementation and improvement of National Essential Medicine System. METHODS： By systematic sampling， 1 728 outpatient prescriptions were randomly selected from a community health service center in Foshan during 2012 to 2015， and then analyzed and compared statistically in respects of the amount of drugs， rational drug use indexes， prescription cost， main disease composition， treatment cost. The change rules and characteristics of all the above mentioned information were all studied. RESULTS： The average number of medicines per prescription and the number of essential medicines decreased year by year，Comparied with 2012， the proportion of antimicrobial agents， the proportion of two or more antimicrobial agents， the proportion of injection prescription and the proportion of transfusion prescription were significantly reduced， the cost of medical treatment of patients decreased significantly； medicine cost and medicare reimbursement amount had increased to different extents， there was statistical significance（P＜0.05）. Multiple linear regression analysis （stepwise） showed that the cost of medical treatment was closely related to rationality of prescriptions. Respiratory diseases， cardiovascular and cerebrovascular diseases， gastrointestinal diseases were the top 3 of the major diseases， the proportion of prescriptions for respiratory diseases， gastrointestinal diseases decreased year by year， while that for cardiovascular and cerebrovascular diseases increased year by year. CONCLUSIONS： The promotion of “New Medical Reform” and the implementation of National Essential Medicine System play a positive role in promoting rational drug use and the quality of medical service in community health service center. However， there are still many problems in the community health service centers， such as too many medicines each prescription， the lack of diagnosis and treatment ability， the defects of medicine selection and administration.