The concept “Diet and Medicine from the Same Source” has been described in old Chinese medical books.  Based on the above classic concept, it has been reported that the various substances (e.g. flavonoids, saponins and tannins etc.) are isolated from various medicinal plants using biochemical and pharmacological assay systems for about 23 years.  In the present review, we will introduce the physiological and pharmacological actions of natural products isolated from the various medicinal plants.