Provided is a novel and practical method for drug evaluation of cilostazol. A method for drug evaluation of cilostazol is used, which uses a thrombin receptor activating reagent and a cAMP-increasing reagent. A platelet function measuring method that includes a step in which a thrombin receptor activating reagent and a cAMP-increasing reagent are brought into contact with a sample originating from blood of patients administered with cilostazol may also be used.
