The methanolic extract of Glycine maxim increased the expression of the promoter in B16 mouse melanoma cells harboring a tyrosinase promoter. Extract concentrations of 10 ${mu}g/m{ell}$ and 100 ${mu}g/m{ell}$ resulted in tyrosinase promoter expression rates of approximately 113% and 184%, respectively, as compared to the control. The fraction layers consisting of butyl alcohol and methylene chloride improved expression effects on the tyrosinase promoter. In particular, the butyl alcohol fraction evidenced a high expression rate at 100 ${mu}g/m{ell}$. In the MTT assay, the methanolic extract did not evidence cytotoxicity at concentrations under 500 ${mu}g/m{ell}$. Therefore, the results observed with the extract of Glycine maxim showed that the substance exerted a positive effect on the tyrosinase promoter.