Inhibitory effect on tyrosinase activity and melanogenesis of the mycelia and mycelial culture broth of Macrolepiota procera were investigated. The methanol fraction of culture broth showed 56.6% of tyrosinase inhibitory activity and its IC50 was 8.78 mg/ml. Using Streptococcus bikiniensis for melanogenesis in vitro, the methanol extract of mycelia showed 94.0% inhibition of melanogenesis.