This paper explores Prof. Li Feiyue’s experience in treating knee pain with internal obstruction of turbid dampness. Prof. Li thinks that with the changes of pathogenesis,the syndrome of superabundance of dampness due to spleen-asthenia,or the syndrome of wind,cold,heat,phlegm and summer-heat can appear in the disease. Therefore the disease is treated with traditional Chinese medicine based on syndrome differentiation,mainly by expelling dampness and resolving turbidity,or by expelling wind and dissipating cold,clearing away heat and expelling summer-heat. It is also treated by external application of traditional Chinese medicine,lotion and manipulation. Two proven cases are presented.