Professor LU Zhizheng proposed the theory of dampness and dryness based on clinical practice.He believes that dryness caused by dampness is a common phenomenon in clinical practice，and the clinical manifestations are specific.The core pathogenesis is abnormal water-liquid metabolism and dysfunction of the opening and closing of Shaoyang Sanjiao，accompanied by pathogenic factors and affected by the characteristics of zang-fu organs.The treatment of dampness-dryness syndrome should be based on the principle of “pungent and moist”，involving the stimulation of Yang Qi，the stimulation of cardinal，the removal of dampness，the moistening of dryness，as well as the application of the method of nourishing spleen with sweet and light herbs，which has provided strategies and methods to solve clinical problems.