Abstract: In this study,the flavonoid compounds in different growth periods of Suaeda salsa were extracted,and their antioxidant and antimicrobial were studied. Ultrasonic method was used to extract flavonoids. Four methods( reducing power,resisting lipid peroxidation,eliminating DPPH·,·OH) were used to evaluate the antioxidant activity of flavonoids extracted from Suaeda salsa.The antibacterial activity was evaluated by Oxford cup method.The results demonstrated that the content of the obtained total flavonoids from Leaf expansion,Germination and Florescence was determined to be 0.728%,0.518%,and 1.461%,respectively.Different growth periods of the alkaline flavonoids had different reduction ability,and activity of removing DPPH· and · OH. The flavonoids of Suaeda in different growth period had a certain of bacteriostatic effect to Escherichia coli,Staphylococcus aureus but that of in florescence expansion inhibition capability( 19.54 mm,29.46 mm) was the strongest. It indicated that the flavonoids extracted from Suaeda can be used as a natural antioxidant and antibacterial agent extensively.