Internet+' education, as an important trend in the development of education cause in the new era, is an inevitable choice to promote the modernization of education. Colleges and universities across the world have carried out teaching reforms to adapt to this brand-new educational form. Especially during the epidemic, online teaching mode has been widely carried out. Colleges and universities have focused on building online teaching platforms to improve the quality of education. This online teaching mode, especially the wide application in medical colleges, has a complex impact on the medical education which was characterized of practicality. Whether the students' professional identity changes due to the shift of teaching mode needs to be explored and studied. The aim of this study was to investigate the current status of medical undergraduates' professional identity during online teaching and its influencing factors. The method applied in this paper was conducted in a medical college in East China in 2022. A questionnaire was used to investigate the status of professional identity, self-directed learning, richness of curriculum resources, teacherstudent interaction and clinical contact of medical undergraduates during online teaching. 718 medical undergraduates scored 3.73 ± 0.57 in professional identity, which is at a moderate level. Professional identity during online study is significantly influenced by the following factors: grade, specialty, online course resources, teacher-student interaction, clinical contact, and self-directed learning ability. Measures to improve theses aspects should be adopted to strengthen the professional identity of medical undergraduates.The development of 'Internet+' promotes the integration of information network technology with education and teaching. In the field of medical education, its characteristics of sharing, diversification and convenience accelerate the construction of a new education system of 'new medical science' in China. While 'Internet +' education brings opportunities to medical education, it also brings many challenges [1] . During the epidemic, most medical colleges adopted online teaching mode for medical education. Face-to-face classroom learning turned into online learning,