Objective Studies have shown that problem based learning (PBL) can improve the students' ability of autonomous learning. However

it is unclear whether students’ autonomous learning ability will affect students’ evaluation in PBL teaching. This study took medical psychology course as an example to explore the influence of medical students' autonomous learning ability on PBL teaching effect. Methods 43 8-year program medical students of grade 2010 and 2011 were enrolled in this study. Scale was used to assess medical students' autonomous learning ability before the start of the PBL teaching. Self-made questionnaire was used to survey the students’ evaluation in PBL teaching. Linear correlation analysis was used to detect the relationship between medical students' autonomous learning ability and students’ evaluation in PBL teaching and their examination results. Results Medical students' autonomous learning ability is significantly positively correlated to the students' evaluation of PBL teaching (P<0.05).The correlation coefficient between learning motivation and PBL enhanced learning interest or PBL enhanced information utilization ability was high (r = 0.507 and 0.536

respectively). It showed that students with stronger autonomous learning ability had more positive evaluation of PBL teaching. The students' learning motivation is also positively correlated to the test score (r=0.416

P=0.006). Students with stronger learning motivation had higher test score in the final exam. Conclusion These results indicate that the relationship between the students' autonomous learning ability and PBL teaching is bidirectional. The students with more powerful ability of autonomous learning will be more active in the process of PBL teaching

while the positive experience will promote their autonomous learning ability in turn.