Abstract: Objective To explore the perceptions of medical students to medical professionalism and its influencing factors. Methods Questionnaires were conducted. Undergraduate students majoring in five-year program, 5+3 integrated clinical medicine, and four-year nursing program in Tianjin Medical University from 2016 to 2021 were selected as subjects. The Simplified Chinese Version Self-assessment tool was adopted to measure student's perception of medical professionalism (the SCV-SPMP). Two surveys were conducted at two different stages of COVID-19 prevention and control in 2020 (phase IV of COVID-19 prevention and control and normalization of COVID-19 prevention and control nationwide). The data were analyzed by Mann-Whitney U rank sum test, multiple linear regression analysis. Results There were 860 students and 693 students participated in two questionnaires respectively, the total score of medical student's perceptions to medical professionalism were [4.7 (0.9)] and [4.6 (0.8)] respectively. The more satisfied from their major,the more are positive to their perception of medical professionalism (b=0.225,P<0.001). Senior medical students’ perception on medical professionalism is lower than those of junior medical students (b=-0.147,P<0.001). Comparing the scores of 375 medical students who participated in both surveys,the total score of the first questionnaire [4.5(0.9)] was higher than that of the second questionnaire [4.7(0.9)] (z=-4.42, P<0.001). Conclusions Medical students' perception to medical professionalism is generally at a high level. Their satisfaction from the major choice and education experience in the medical school are the factors that affect medical students' perception of medical professionalism. COVID-19 pandemic has an impact on medical students' perceptions of medical professionalism.

Key words: Students, medical, Medical professionalism, Perception, COVID-19 pandemic