Objectives: This study was performed to elucidate the effects of Kwibi-tang extract(KB) on dermal fibroblast. Methods: To demonstrate the effects of KB on dermal fibroblast, we used human dermal fibroblast(F6) and UVB light(30 $mJ/cm^2$) was used to damage to dermal fibroblast. we measured the nitrite production, LDH release in UVB-irradiated dermal fibroblast to elucidate the action-mechanism of KB. Also, we evaluated cell proliferation of dermal fibroblast and the amount of increased PICP, TIMP-1 in dermal fibroblast. Results: 1. KB decreased the cell proliferation of F6 dermal fibroblast in concentration of 50 ${mu}g/ml$. 2. KB decreased the synthesis of PICP in concentration of 50 ${mu}g/ml$. 3. KB decreased the synthesis of TIMP-1 in concentration of 50 ${mu}g/ml$. 4. KB have no effect on the damage in UVB-irradiated F6 dermal fibroblast. Conclusions: From the results, we concluded KB decreases the cell proliferation and collagen synthesis in dermal fibroblast. So we suggest that KB has the anti-hyperplasy of dermal fibroblast.