By reading the literature about Mr.SUN Bingyan, his characteristcs and experience in treating cancers of digestive tract were summarized.In clinical practice, Mr.SUN integrated traditional Chinese and western medicine, treating cancers mainly by Chinese materia medica, with chemotherapy drugs as a supplement.He believed that cancers were caused by cancer toxin.Thus, in treatment of cancers, the "counteracting one toxin with another" method should be used.Mr.SUN advocated the concept of preventive treatment of disease and believed that the "three early steps" (i.e.early prevention, early detection and early treatment) were significant to the prevention and treatment of cancers.He used Huangyaozi(Dioscoreae Bulbiferae Rhizoma), Xuduan(Dipsaci Radix) and Shayuanzi(Astragali Complanati Semen) well in treatment of cancers of digestive tract, with reinforcing yang and attacking toxin as the main method, especially appreciating purgative therapy and toxin-eliminating therapy.