PURPOSE: To obtain a skin external preparation, containing a tranexamic acid derivative and having excellent beautifying and whitening effects and preventing and improving effects on skin roughening.

CONSTITUTION: This skin external preparation contains at least one or more of an tranexamic acid derivative expressed by formula I [R is expressed by formula II or morpholino; (n) is 2-7] and its salt as active ingredients in an amount of 0.001-20wt.%, preferably 0.01-7wt.% based on the total amount thereof. The skin external preparation is prepared by suitably blending an oil, an ultraviolet light absorber, an antioxidant, a surfactant, a humectant, a perfume, water, an alcohol, a thickening agent, a colorant, a skin nutriment, etc., besides the compound expressed by formula I. tans-4-Aminomethyl-1- cyclohexanecarbonylaziridine amide is exemplified as the compound expressed by formula I contained therein.