Objectives : The goal of this paper is to research what the name and concept of true-cold damage in Introduction to Medicine were originated from, and to trace the origin and changes of categorization of it after the book. Methods : Books concerned with true-cold damage were collected as many as possible, besides ones that Introduction to Medicine referred to, before the name, concept and categorization of it were searched and analysed. Results : The concept of true-cold damage in Introduction to Medicine, which had come from Lei Zheong Huo Ren Shu(類證活人書) in Song dynasty, was more similar to one of cold damage in a broad sense. The name that Li Chan appreciated, was derived from not Shang Han Zhi Ge(傷寒直格), but Shang Han Zheng Zhi Ming Tiao(傷寒證治明條) in Song dynasty. On the other hand, since Tao Hua(陶華) began to go into the details of cold damage in a narrow sense, most books had followed it. Whereas 11 diseases among 24 diseases of true-cold damage in Introduction to Medicine indirectly came from Lei Zheong Huo Ren Shu(12 diseases), 14 diseases among them were directly derived from Shang Han Zheng Zhi Ming Tiao(16 diseases) and 10 diseases were added containing syndromes of retained fluid and jaundice. The categorization in Introduction to Medicine scarcely adopted except Donguibogam(東醫寶鑑) and Uimunbogam(醫門寶鑑), while the categorization of true-cold damage in a narrow sense was mostly composed of 2 diseases, that is cold damage(傷寒) and wind damage(傷風). Conclusions : Li Chan had fulfilled the total conditions in which the concept, cause, symptoms, prescriptions and prognosis of 24 diseases in true-cold damage were equipped, in order to build up the system and categorization of it. To our regret, his scientific outcome had been hardly referred after his book.