Objectives(1) Understanding the characteristics of online learning experiences of Chinese undergraduate medical students; (2) Investigating students’ perceptions of ongoing online education developed in response to COVID-19 and (3) Exploring how prior online learning experiences are associated with students’ perceptions.DesignStudents’ familiarity with online learning modes and corresponding perceived usefulness (PU) according to their previous experiences were investigated using an online survey. The survey also collected data on students’ perceptions through their evaluation of and satisfaction with current online learning.SettingIn response to the educational challenges created by COVID-19, medical schools in China have adopted formal online courses for students.ParticipantsThe questionnaire was sent to 225 329 students, of whom 52.38% (118 080/225 329) replied, with valid data available for 44.18% (99 559/225 329).MethodsPearson correlations and t-tests were used to examine the relationship between familiarity and PU. Multiple linear regression and logistic regression analyses were used to determine the impact of prior learning experiences and its interactions with gender, area, learning phase and academic performance on students’ perceptions.ResultsStudents’ PU had a significant positive correlation with their familiarity with online learning modes (p<0.01). Students’ evaluation of and satisfaction with their current online education were positively associated with their familiarity (β=0.46, 95% CI 0.45 to 0.48, p<0.01; OR 1.14, 95% CI 1.13 to 1.14, p<0.01) with and PU (β=3.11, 95% CI 2.92 to 3.30, p<0.01; OR 2.55, 95% CI 2.37 to 2.75, p<0.01) of online learning. Moreover, the higher the students’ learning phases, the lower the associations between PU and students’ evaluation of and satisfaction with ongoing online education.ConclusionsMedical students in China have experiences with various online learning modes. Prior learning experiences are positively associated with students’ evaluation of and satisfaction with current online education. Higher learning phases, in which clinical practices are crucial, and high academic performance led to lower evaluation and satisfaction scores.