Abstract: The effect of the degree of hydrolysis(DH) on the emulsification,foaming capacity and antioxidant activity of Spirulina peptides was investigated. The DH of the hydrolysate increased during the process of hydrolysis. In the process of hydrolysis,the foaming activity,DPPH radical scavenging ability,and reducing power of Spirulina peptides first increased then decreased with the increase of the DH,the hydroxyl radical scavenging ability first decreased then increased,when reached maximum then decreased,however the foaming stability,the emulsification,emulsifying stability decreased with the increase of the DH. This showed that the DH was not the higher the better in the production of Spirulina peptides,and the best DH must be determined according to the need of the products to get a better physicochemical properties and antioxidant abilities.