Differentiation and treatment of diabetic foot, four Evil factors, namely, Sugar, Stasis, Turbid and Heat Evil factors, should be stressed. Sugar Evil factor is a poisonous Evil produced by the overwhelming storing of nutrition within body. It is also the basis of diabetes and its complications. Stasis and Sugar Evil factors are the causative factors throughout the entire course of diabetic foot. The Evil of Turbid poison can consume the Lung Yin in the upper Burner, burn the stomach Yin in the middle Burner, and consume Kidney Yin the lower Burner. When they enter into blood circulation, the veins would be injured and the blood would become rotten. The descending of Turbid Evil would lead to edema of the foot. With time, the Heat induced would cause foot necrosis infection. Suger, Turbid Stasis Evil factors can all become Heat toxins over time. It is emphasized that the diabetic foot infection period must be dominated by Damp and Heat Evil factors. Diabetic foot can be divided into ischemic period, infection necrosis period and recovery period, and that should be treated according to the character of different stages. The treatment methods are activating blood circulation, removing blood stasis and detoxification is used in the ischemic phase; the method of clearing heat, removing turbidity and detoxification is used in the infection and necrosis phase; the method of activating blood circulation, removing blood stasis and detoxification in the ischemic phase.