Abstract
The medicine through I Ching(The Book of Changes, 易經) is a field of the medical science, which studies physiology, pathology and Yin-Yang philosophy. From ancient times so many scholars have studied I Ching and they are divided into two different school. one is the school of Image and Number(象數學派), the other is the school of reason(義理學派). Dasan Jung Yak-Yong(茶山 丁若鏞) is a distinguished scholar in the I-Ching study, and he had a unique opinion in the analysis about sentences of I Ching. He has done his best to make 'Image and Number(象數)' harmonize with reason(義理). I Ching is the book about changes, which includes everything like natural phenomena, human body and mind. So we can understand human physiology and pathology through I Ching.