PROBLEM TO BE SOLVED: To provide a cosmetic having dullness improving effect.SOLUTION: A skin external agent contains 1) triterpene acid or a derivative thereof and 2) a YAC compound having the following characteristics and/or salt thereof. The characteristics of the compound have: (1) a &lambdamax at 405-415 nm and at 660-670 nm (2) 1H-NMR spectrum shown in Figure 1 (3) 13C-NMR spectrum shown in Figure 2 (4) a single peak shown before and after 15 minutes in HPLC analysis under the following conditions (mobile phase: 90% acetonitrile column: ODS 4.6×250 mm flow rate: 1 ml/min. temperature: 40°C and detection: ultraviolet part 210 nm) and (5) a chemical composition formula of C34H40O9 and a mass analysis spectrum of 593(M+H). The triterpene acid is preferably selected from ursolic acid, oleanolic acid, asiatic acid and betulinic acid.
