Professor NAN Zheng first put forward the diabetic nephropathy’s TCM name as Xiaoke Shenbing.Through the research and discussion of “poison evil “and “kidney collaterals“ , Professor NAN Zheng pointed out that toxin is the pathogenic factor of diabetic nephropathy, The key pathogenesis is “kidney collaterals impaired by toxin“ , and throughout the course of the disease.In the process of treatment, the essence of the disease is grasped by getting the key of pathogenesis of"kidney collaterals impaired by toxin".After suffering from diabetes for a long time, the pathological products such as phlegm, damp heat, stasis, etc.Produced by the body and become the pathogenic factors “toxin“ .Toxin attack the kidney collaterals, cause the blood collateral of the kidney to swell, the kidney to be injured, and the normal physiological function of the kidney changed, so as to form diabetic nephropathy.Professor NAN Zheng created an effective prescription Xiaoke Shen’an Decoction for the treatment of this disease, which is composed of 15 traditional Chinese medicines such as hazelnut flower, rhubarb, tuckahoe and astragalus, etc.This prescription consists of four kinds of herbs:detoxifying and unblocking collaterals, strengthening kidney, removing blood stasis and unblocking collaterals, guiding pathogenic factors and unblocking collaterals.These four kinds of herbs play a role in protecting the kidney and treating diabetic nephropathy.This prescription has a good effect in clinical application.