Abstract: Knee Osteoarthritis (KOA) is a common disease in clinic affecting life quality， especially obese people after middle age. With years of great clinical experience， Professor Zhou Fu-yi holds that its main pathological mechanism is the deficiency of liver and kidney as well as interrelation between phlegm and stasis and suggests that reinforcing liver and kidney and dissipating phlegm and removing blood stasis should be applied in treating knee osteoarthritis with significant treatment effect and worth of clinical application.