In this study, papaya and muskmelon extracts seem to have high antioxidant potential, especially papaya peels (PS) and muskmelon peels with IC50 value of 0.75±0.01 and 1.20±0.01 mg mL-1, respectively. This indicates that two of them are possibly applied as a strong antioxidant for replacing the use of synthetic ingredient on cosmetics. Moreover, the use of wastes from Royal Project’s fruits will be an alternative way for value-add the wastes and subsequently increase the income of Thai’s agriculturist.