Abstract: Since The Yellow Emperor's Inner Classic put forward the concept of retrograde treatment， physicians from different period of history had studied it from different perspectives. According to the feature of Inner Classic， the concept of retrograde treatment must be concise， which means that it is the opposite treating method based on reverse thinking. Wang Mengying was the famous doctor of epidemic febrile disease of later Qing Dynasty. When treating diseases， he would find the roots and it was quite useful in the treatment.