The inhibition mode of S-hydroxy-2-phenylalanylaminomethyl-4-pyron ($IC_{50}=24.6{;}{mu}M$) on mushroom tyrosinase was investigated using L-tyrosine as a substrate. This inhibitor is the kojic acid derivative, where the C-7 hydroxyl of kojic acid was replaced by amino group and coupled to the carboxyl of L-phenylalanine. The kinetic data obtained show a competitive inhibition pattern.