Objective: This study was carried out to investigate the effects of Gami-Shengmayuipung-tang on acne. Methods : The effects of Gami-Shengmayuipung-tang (SYTSRG) on acne were measured by the $5alpha-reductase$ inhibition, the sterilizing power for Propionibactrium acnes, the cytotoxicity of human monocyte, the inhibition for prostaglandins$(PGE_2)$, interleukins $(IL-leta)$ and $TNF-alpha$ in inflammation, and the size of the hamtster ear sebaceous gland related to P. acnes. Results: On the $5alpha-reductase$ inhibition of SYTSRG in vitro, an undiluted solution of SYTSRG showed $80\%$ inhibition on $5alpha-reductase$ and 1/10 diluted solution of SYTSRG showed $40\%$ inhibition on $5alpha-reductase$. On the sterilizing power for Propionibactrium acnes related acne, an undiluted solution and 1/10 diluted solution of SYTSRG formed $12eta{AE}$ clear zone diameters. SYTSRG did not show cytotoxicity of human monocyte. Concentrations of $0.01\%;and;0.04\%;and;0.08\%$ of SYTSRG inhibited the production of prostaglandins $(PGE_2)$ in the human monocyte stimulated with P. acnes LPS. $0.08\%$ and less of SYTSRG inhibited the production of interleukins $(IL-leta)$ in the human monocyte stimulated with P. acnes LPS. Concentrations of $0.04\%,;0.08\%;and;0.12\%$ of SYTSRG inhibited the production of $TNF-alpha$ in the human monocyte stimulated with P. acnes LPS. As the antiandrogenic compound, SYTSRG was used in hamster ears with topical application. SYTSRG diminished the size of the hamster ear sebaceous gland in males, but not in females. Conclusion: The present data suggest that SYTSRG may affect the primary stage of inflammation of acne.