Four series of derivatives of vanillin,anisaldehyde,genistein and aloe emodin were prepared.The single crystal of （E）-1-（5-（4-methoxyphenyl）-3-（4-methoxystyryl）-4,5-dihydro-1H-pyrazol-1-yl）ethanone,which was synthesized from vanillin, was obtained by spontaneous evaporation method.All the compounds were tested for the tyrosinase inhibitory activities.The results demonstrated that the IC_（50）values of vanillin,anisaldehyde,genistein and aloe emodin against mushroom tyrosinase activity are 68,49,343 and 160μM,respectively.Among the twelve derivatives,（E）-1-（5-（4-methoxyphenyl）-3-（4-methoxystyryl）-4,5- dihydro-1H-pyrazol-1-yl）ethanone from vanillin and 4,5-dimethoxy-9,10-dioxo-9,10-dihydroanthracene-2-carboxylic acid from aloe emodin showed good inhibition against the tyrosinase with IC_（50）values of 18μM and 21μM,respectively.
