Six-channel syndrome differentiation and viscus syndrome differentiation belong to the syndrome differentiation theories of different dimensions,instead of the one-to-one correspondent relationship.In order to further clarify the connotation of Taiyin disease theory in Treatise on Cold Pathogenic Diseases,by careful study and analysis of the text of Treatise on Cold Pathogenic Diseases,the author illuminated that the essence of connotation of Taiyin disease theory is that Taiyin disease itself lies in the eternal,its property is cold,and its trend is deficient;and that Taiyin water disease and Taiyin blood disease are the two basic pathogenic mechanisms of Taiyin disease.Meanwhile,based on the text and basic pathogenic mechanisms,discussed the opinion that Taiyin disease may involve various viscera and their syndromes,including heart,liver,spleen,lung,kidney,stomach and so on.