There are important differences between evidence-based medicine and traditional medicine. Traditional medicine is based on personal experience, and doctors treat patients according to their own practical experience, the guidance of senior doctors and scattered research reports in textbooks and medical journals. The results are as follows: (1) Some truly effective therapies have not been used in clinic for a long time because they are not known to the public; Some therapies that are ineffective or even harmful in practice have been widely used for a long time because they may be effective in theory. Evidence-based medicine not only attaches importance to personal clinical experience, but also emphasizes the use of existing and best research evidence, both of which are indispensable. The basis of this study mainly emphasizes the evidence of clinical research. (Excerpted from Professor Wang Jialiang's lecture in April 2000)