OBJECTIVE： To study the antioxidant activity of the different polar parts from Dictamnus dasycarpus and its effects on tyrosinase activity. METHODS： Extract was extracted by 95％ ethanol from D. dasycarpus， using petroleum ether， chloroform， ethyl acetate to obtain different polar parts after dissolved in water. 1，1-diphenyl-2-trinitrophenylhydrazine （DPPH） method was used to investigate its antioxidant activity [expressed as half inhibitory concentration （IC50）]， and tyrosinase method was used to investigate the related activity in different polar parts. RESULTS： The IC50 of petroleum ether， chloroform， ethyl acetate parts for scavenging DPPH free radicals were 0.875， 0.824， 0.407 mg/mL， respectively. When the mass concentration of each polar part were 25.0， 50.0， 100， 200， 300， 400， 500 μg/mL， the inhibition rate of petroleum ether part to tyrosinase were －3.18％，      －4.98％， 0.160％， 0.044％， 2.31％， 3.89％， 4.29％； that of trichloromethane part were －33.39％， －31.48％， －10.14％，      －5.42％， －9.70％， －4.06％， －0.42％； and that of ethyl acetate part were －17.63％， －17.89％， －18.42％， －21.84％，       －20.26％， －22.13％， －32.36％. CONCLUSIONS： The capacity in scavenging DPPH free radicals in ethyl acetate part is obviously stronger than the other 2 parts， showing positive correlation with the concentration. Ethyl acetate and chloroform chave an activation effect on tyrosinase， the activation effect of chloroform part on tyrosinase was negatively correlated with the concentration and petroleum ether part has a two-way regulatory effect on the activity of tyrosinase.