Laboratory animals are commonly used as experimental objects in medical research, and laboratory animal welfare is closely related with good scientific outcomes. It is important for researchers in hospitals to establish a concept of protecting the welfare of laboratory animals. In this paper, combined with our experience concerning with the ethics and animal welfare in recent years in Nanjing Drum Tower Hospital, the Affiliated Hospital of Nanjing University Medical School, we try to discuss the importance of animal experiments in the hospital, the significance of maintenance of laboratory animal welfare and the ethical review of the welfare of laboratory animals, etc., in order to provide a reference to the protection of laboratory animal welfare for researchers in hospitals.