Background: Ultra Violet (UV) sun radiation has both positive and negative effects on health. The detrimental effects caused by UV rays vary depending on the level of UV energy, intensity, and sensitivity of the skin of each individual. Sunlight radiation can emit a spectrum from the UV to the infrared. UV radiation in the UVC region (200-290 nm) to UVB (290-320 nm) is harmful to the skin. Natural antioxidants and sunscreens can be obtained from plants that contain flavonoids, one of which is the buni plant (Antidesma bunius (L.) Spreng). Buni (Antidesma bunius (L.) Spreng) is a plant that has the potential to be developed as an antioxidant. The purpose of this study was to determine the antioxidant activity and determine the SPF value of ethanol extract of buni leaves. Method: Extraction using remaseration method with 70% ethanol solvent and determination of antioxidant activity using DPPH (2,2-diphenyl-1-picrylhydrazil) method, FRAP (Ferric Reducing Antioxidant Power) and Determination of SPF (Sun Protectin Factor) values with the Mansur equation. Results: The antioxidant activity test of Buni leaf ethanol extract based on DPPH method has a very strong antioxidant activity with IC50 value of 7.563 μg / mL. Based on the FRAP method the antioxidant activity produced is strong with IC50 of 62.662 μg / ml and the SPF value of the ethanol extract of buni leaves at a concentration of 200 μg / ml 6.58 has extra protection in protecting the skin against UV rays. Conclusion: Buni leaf ethanol extract has strong antioxidant activity with DPPH and FRAP methods and has a photoprotective effect in protecting the skin against UV rays.