The article analyzed the correlations and differences among formative,summative and comprehensive assessment of six clinical courses with SPSS. The results showed that summative assessment was more effective and had a significant correlation with comprehensive assessment no matter the proportion, and the correlation between formative and comprehensive assessment was related to the big proportion of formative assessment. These results suggested that it was necessary to adjust and clear the goal and requirement of course assessment, different methods of assessment should be applied to different goals and requirements of assessment,and many methods of formative assessment for existing courses should be further improved.