Objectives Yusanghan(類傷寒) means disease which chills and fever manifest like Cold damage(傷寒) but not Cold damage. However, study on Yussanghan is insignificant. The purpose of this study is to examine the origin and development process of Yusanghan. Methods: 1. Terms and disease related with Yusanghan was collected from books covering Cold damage of all time and analyzed. 2. The transition history was researched by analyzing collected terms. 3. Total appearance frequency of all time by collected disease was researched. Results: Yusanghan was appeared in Hwalinseo(活人書), which Ju Geong(朱肱) of the Song Dynasty wrote, for the first time and the definition and type were established. For the types of those, there are four diseases such as Phlegm-Fluid Retention(痰飮), Food Accumulation(食積), Vexation of Deficiency Type(虛煩), Beriberi(脚氣). Since then, the theory about Yusanghan had developed and the number of types had also increased until the Myung Dynasty. Conclusions: In early days, External Contraction Diseases(外感病) was not included in Yusanghan, but since the late Myung Dynasty, there were a lot of doctors who included External Contraction Diseases in Yusanghan, not in Cold damage. There are Summerheat Stroke, Wind-Dampness(風濕), and Warm Disease(溫病) etc. for included External Contraction Diseases. Because of this, the number of types of Yusanhan had significantly increased.