Objective To scientifically evaluate medical students' comprehensive quality. Methods Self-made questionnaires was used to survey in 2138 students of some medical universities(latitude study). The freshmen were evaluated every 6 months, and the results were analyzed (longitude study) respectively with paired test, repeated measures of ANOVA and data envelopment analysis. Results The comprehensive quality score of the medical students was (0.934±0.037), and the ranking of the concrete qualities was: psychology>specialty>body>morality>basic ability>science-culture. The comparison between adjacent evaluations showed that science-culture, psychology and basic ability quality in the second evaluation were advanced relative to those in the first, still specialty and body quality were on the contrary. The comparison among the three evaluations showed that thecomprehensive quality and all the concrete qualities were boosted of different magnitudes and the comprehensive quality was improved in general, especially in the later period. Conclusions The latitude study is contributed to generally grasp the quality’ status and characteristics of medical students. In longitude study, the effects of quality education in different stages are gotten and quality education is showed effectively, the subjective efforts of students are good as well.