It is commonly believed at present that the Treatise on Cold Pathogenic Disease（ 伤寒论） initiated the treatment based on pattern differentiation

and pattern differentiation of eight principles are the general principle.Therefore it is believed that pattern differentiation based of eight principles is reflected throughout the book

thus the concept of cold and heat in Treatise on Cold Pathogenic Disease（ 伤寒论） is taken the same as that in the "eight principles". The viewpoint no doubt covers the objective law of the concept evolution in traditional Chinese medicine（ TCM）. Influenced by different historical backgrounds in different historical periods

the concept evolutes gradually.This paper gives an interpretation to the connotation of cold and heat in the pattern differentiation of eight principles and in the Treatise on Cold Pathogenic Disease（ 伤寒论）. Differentiating the meanings of cold and heat helps to clarify the evolution of the concept of cold and heat in historical process

and is of guiding function on other concepts in TCM

at the same time it is of great significance on the study of TCM academic history.