Smile is one of the representations of the professional attitude of medical staff; it is not only the expression of sympathy, understanding and care of patients, but also directly to show the cultivation and quality of medical personnel. We used a self-designed questionnaire to investigate the current smile status and smile reasons in the medical staff, and the differences of the patients’ feedback between the different patients. Through the study, we found that the medical staff’s smile represents the hospital culture and hospital image, showing the overall spiritual outlook of the hospital; Smiling service is the key factor to improve the quality of health care and build a good doctor-patient relationship, which is of great significance to improve the quality of outpatient service, patients referral rate and satisfaction of patients. Smiling service can eliminate the patient’s nervous mood, relieve pain, close relationship between doctors and patients, and promote the development of the harmonious relationship between doctors and patients.