In Traditional Oriental Medicine, the drug treatment has been explained by the thoery of "Si Qi Wu Wei(四氣五味)". Among them, Xin(辛) has effect of Sheng(升), San(散), Xing(行), and Ku(苦) has effect of Jiang xia(降下), Zao shi(燥濕), Jian yin(堅陰). The study on the medical action of Asari Radix shows that "Xin ke run zao(辛可潤燥)" was derived from Sheng(升), San(散), Xing(行) efficacy of sour. And the study on the medical action of Phellodendron Bark, Anemarrhenae Rhizoma shows that "Ku ke run zao(苦可潤燥)" was derived from Xie(泄) efficacy of bitter.