studying on si-dong and so-seng diseases recorded in lyeong-chu, kyeong-maek, the authors take out the results as follows. 1. si-dong diseases are caused by chang-fu organs(臟腑) itself and separately concerned with chin(津), hyeol(血), ki(氣), ek(液), keun(筋), kol(骨). 2. so-seng diseases are caused by invasions of six climatic conditions in excess as pathogenic factors(六淫) on the meridiain and collaterals. 3. si-dong diseases are mainly chronic and deficient syndromes. 4. so-seng diseases are mostly excessive and acute syndromes.