Abstract:Objective：By analyzing the data of letters and complaints from acertain grade A tertiary hospital in Nanjing from 2017 to 2020，we can understand the main causes of hospital letters and complaints，and provide guidance for further improving patient satisfaction and medical service quality. Methods：A retrospectively analysis was used for 2，902 letters and complaints of acertain grade A tertiary hospitalsin Nanjingfrom January 2017 to December 2020. The sources of letters and visits，the total number of letters and complaints and the volume of business，types of appeals and satisfaction with complaint handling were compared in the past four years. Results：Among of 2，902 letters and visits，complaints accounted for 87.04%. In 2020，due to the influence of COVID-19，the volume of business declined，but the volume of complaints increased. The main source channel of patients’ complaints was 12345 government affairs hotline platform，accounting for 56.57%. The main categories of complaints were medical technology（27.15%），service attitude（23.20%）and hospital management（14.6%）. Patients were less satisfied with the first result of complaint handling（79.13%）. Conclusion：In order to reduce the occurrence of complaints，the hospital should establish and improve the complaint mechanism，and strengthen the closed-loop management of complaints，strengthen the construction of medical ethics，pay attention to improving the medical experience of patients.