Objective　To investigate and compare the clinical thinking ability of medical graduate students of different majors and different grades to explore the influencing factors of clinical thinking ability. Methods　180 graduate students in Medical College of Qingdao University were sur-veyed，including 54 nursing and 126 clinical medicine graduates of different grades. We used a self-designed scale of clinical thinking ability which included three main dimensions（critical thinking abil-ity， systematic thinking ability， evidence-based thinking ability） and twenty-four level 2 items. Ap-plying t test， ANOVA， multiple linear regression analysis for data statistical analysis. Results　There's no significant difference comparing the scores of nursing graduates to the scores of clinical medical graduates（t=-0.80， P >0.05）. However， there is significant difference in the different grade graduates（F=53.43， P<0.05）. The multiple linear regression analysis shows that the practice time， reading professional literature quantity， and starting research earlier or later，are signif-icantly related to the clinical thinking ability（P<0.05）. Conclusion　The clinical thinking level of medical graduate students is generally high， and the higher grade， the higher level of clinical think-ing ability. We must strength-en the training of clinical thinking ability of medical graduates.