Professor LIU Xianlin is one of the founding seniors of Shandong University of Traditional Chinese Medicine, a famous researcher of Zhongjing’s theory.Professor LIU has extensive knowledge from his family and others, and he has rich experience in clinical practice and unique academic ideas.Professor LIU believes that the idea of prevention of diseases is the essence of Zhongjing’s theory. "Take measures to prevent disease from occurring, prevent disease from transmission" . Professor LIU uses the four diagnostic methods especially paying attention to tongue diagnosis and pulse diagnosis, and he is good at taking tongue and pulse diagnosis into account without symptoms. "Pathogenesis must be carefully examined according to the nature of diseases." Professor LIU Xianlin’s use of prescriptions is accurate, treating both the internal and the external, the branch and the root.LIU Xianlin is experienced in internal medicine especially good at using several small formulas to treat lung diseases such as cough.In the treatment of cough, LIU Xianlin emphasized the importance of syndrome differentiation, and created the "three-step syndrome differentiation method" to differentiate the internal and the external, determining the Zangfu-organs, deciding the deficiency and excess.In compatibility, Professor LIU emphasizes dispelling wind as the first priority, attaches importance to the relationship between exogenous affection and internal injuries, and attaches importance to aftercare.Diagnosis and treatment of cough provides mature ideas of syndrome differentiation and valuable experience.