Sun radiation contains ultraviolet rays consisting of UV-A, UV-B, and UV-C. This ultraviolet light can cause adverse effects on the skin such as the appearance of sunburn (erythema), pigmentation, skin aging, and can also cause skin cancer (melanoma). To reduce the adverse effects on the skin, it is necessary to use sunscreen that protects the skin from exposure to ultraviolet rays. Brown seaweed is one of the natural ingredients that can be used as a natural ingredient for sunscreen. This is because genetically brown seaweed is more often exposed to sunlight so it can synthesize components that can absorb ultraviolet light. Sargassum sp. It is known to have polysaccharide compounds such as alginate and fucoidan which have potential as antioxidants and anti-inflammatory. The purpose of this study was to determine the photoprotective activity of the polysaccharide compounds found in Sargassum sp.