This study was designed to investigate the chemical composition of red algae Gelidium sp. collected from Mediterranean sea as new source of bioactive substance. The biochemical components for this algae were isolated and characterized which includes amino acids and fatty acids. Protein was extracted and characterized. The functional properties which includes foaming capacity and foam volume stability, emulsifying properties , water binding capacity and oil binding capacity. Polysaccharides from this algae was extracted and characterized which includes sulfate content, mono saccharides composition , antioxidant activity which includes, the free radical scavenging capacity using a 1,1-diphenyl-2-picrylhydrazyl (DPPH) and the scavenging activity against the hydroxyl radical. Further studies were conducted to biological effects of gelidium algae on rates. The proximate chemical composition of Gelidium sp. were protein content (13.23 ± 1.06% DW) , crude lipid (1.16 ± 0.21% DW), fiber content (5.5 ± 1.05% DW) , ash content (26.45 ± 0.74%) , and carbohydrate content (53.66 ± 1.21% DW).