The water-soluble protein,salt-soluble protein and insoluble protein were separated from Crassostrea rivularis Gould,and the three protein fractions were hydrolyzed by trypsin and alkaline protease. The degree of hydrolysis( DH) under different time was determined. The solubility and emulsifying capacity of protein hydrolysates with different degree of hydrolysis were investigated. The results showed that the solubility of protein hydrolysates prepared by alkaline protease was better than that by trypsin. The degree of hydrolysis was higher and the solubility was better as the hydrolysis time was longer. But protein emulsification and emulsion stability showed a rise at first followed by a decline. When the DH reached 7%,the emulsification and emulsion stability of water-soluble protein reached maximum,and the emulsifying capacity of salt soluble protein and the insoluble protein were better at the degree of hydrolysis of 5. 8% and 5. 7%,respectively. Limited hydrolysis could improve the solubility of oyster protein and improved the emulsification to a certain extent. These results will provide theoretical basis for the further use of oyster protein resource.