Abstract. Brown algae are leading commodities with high nutrients, and potential bioactive compounds. Furthermore, the seaweed contains carbohydrates, proteins, ash, water, vitamins and macro and microminerals, edible by humans. This study aims to determine the chemical and phytochemical characteristics of S. filipendulla brown algae in the Kelanit waters of Southeast Maluku. In addition, this research carried out the proximate analysis, mineral content test, and phytochemicals of ethanol extract. The results showed the chemical composition of S. filipendulla comprised 21.61%, 24.79%, 0.19%, 2.31%, and 52.20% of water, ash, fat, protein, and carbohydrate content respectively. Furthermore, the mineral level consisted of 21.52 mg/g, 0.50 mg/g, 21.53 mg/g and 27.60 mg/g of magnesium (mg), Iron (Fe), Sodium (Na), and Potassium (K) correspondingly. Also, the phytochemical analysis showed the presence of phenol, tannins, flavonoids, saponins, and steroid compounds. Therefore, the active compound production of brown algae S. filipendulla is estimated to be alternative disease prevention in Indonesian aquaculture.

Key Words: Chemical Characteristics, Phytochemicals, Brown Algae, Sargassum filipendulla