Purpose This study is intended to catch the expansion of theory of Sasang Constitutional Medicine through comparison prescription of Sasang-Yihak-Chobonguen with prescription of Dongyi-Soose-Bowon Method I studied the archive of prescription and medicines concerned in the Sasang-Yihak- Chobonguen with Dongyi-Soose-Bowon Result and conclusion 1. The base of theory on prescription of Sasang-Yihak-Chobonguen is based on Naesang -oigam theory but the base of theory on prescription of Dongyi-Soose-Bowon is based on Pyoribyung theory of Sasang constitutional Medicine. 2. Medicines are confused in prescription of Sasang-Yihak-Chobonguen but medicines are not confused in prescription.