In the light of the theory stated in Canon of Internal Medicine and other related theories expounded by specialists of past ages, this article proposes that proteinuria has an analogy with the refined nutritious substance leaking from the spleen and kidney in traditional Chinese medicine. The pathological change, zheng-differentiation and treatment of proteinuria in nephrotic syndrome are also discussed. Through years of his clinical experience, the author recommends some kinds of herbal medicines effective for treating proteinuria. This article, therefore, provides not only a theoretical basis, but also clinical experience for the treatment of proteinuria in nephrotic syndrome.