To discuss the inhibiting mechanism of water extraxt solution from Rhodiola on theTyrosinase activity.Tyrosinase inhibiting rate is determined and Lineweaver-Burk curve is made by determining the tyrosinase activity before and after drug（water extract solution） interference oxidant of method,on which we deduce the inhibiting types of the drug.The water extract solutioncan inhibit the tyrosinase activity remarkably with the half inhibiting concentration IC50 3.9g/L.The water extract solution can inhibitthe tyrosinase activity and it is thenoncompetitive inhibitor of tyrosinase.
