Abstract: In this study,two polysaccharides of Spirulinaplatensis called S₁ and S₂ were prepared by water extraction.The polysaccharides of Spirulinaplatensis were selected from A,B,C,D and E by different concentrations.We used Drosophila melanogaster as experimental animals to mensurate Peroxidase (POD),catalase (CTA),superoxide dismutase (SOD),glutathione peroxidase (GSH) and malondialdehyde (MDA) contents of different sex in medium given above.The results showed that the activities of CAT,POD,SOD and GSH in Drosophila melanogaster were significantly increased,but the content of MDA decreased obviously.And the activities of SOD,CAT,POD,GSH-PX and the content of MDA in male Drosophila are slightly higher than those of female fruit flies.

Key words: spirulina polysaccharide, drosophila, antioxidant capacity