This experimental study was performed to investigate the anti-inflammatory effects of Phellodendri Cortex(PC), Indigo Naturalis(IN). Alumen(AM), and Chinensis Galla(CG). These four prescriptions most frequently have been used in of oriental medicine for the external the theraphy of Gu-Chang. This study was done to evaluate the activity of superoxide dismutase(SOD) and the inhibitory effects of the formation of cyclooxygenase-2(COX-2), tumor necrosis $factor-{alpha}(TNF-{alpha}),;interlenkin-1{eta}(IL-1{eta})$, prostaglandin-E2(PGE2) on the monocyte and neutrophil. The results were summerized as follows. 1. IN has no cytotoxicity but PC, AM, CG have a little cytotoxicity by the increase of concentrations. 2. PC, IN, AM and CG all inhibited the formation of COX-2 in the human neutrophil. 3. $1000{mu}g/m{ell}$ of PC increased the formation of SOD in the human monocyte. 4. $1000{mu}g/m{ell}$ of PC, $100{mu}g/m{ell}$ and $1000{mu}g/m{ell}$ of IN, $100{mu}g/m{ell}$ of CG inhibited the formation of $TNF-{alpha}$ in the human monocyte. 5. $10{mu}g/m{ell}$ of PC, $1000{mu}g/m{ell}$ of IN inhibited the formation of $IL-1;{eta}$ in the human monocyte. 6. PC, IN, AM and CG all did not inhibit the production of PGE2 in the human monocyte In addition, the results show that PC, IN, AM and CG all have anti-inflammatory effects and can be used fer the external theraphy of Cu-Chang.