Enzyme-assisted aqueous extraction process is a green oil extraction technology,which has advanced in recent years, may be a effective alternative technology to separate oil and protein from soybeans. It will be accompanied by cream, skim and residual fraction in the enzymeassisted aqueous extraction process．The main component in the skim is soy protein hydrolysates. Different types of proteases (Alcalase, Neutrase, Papain, Bromelain, Flavourzyme, Protamex and Trypsin) were used to hydrolyze the extruded soybean flour. Different kinds of protein hydrolysates were used as the research objects. The structure of soybean protein hydrolysates was characterized by degree of hydrolysis, SDS-polyacrylamide gel electrophoresis, amino acid composition analysis and Fourier transform infrared spectroscopy. Solubility, emulsion activity index and emulsion stability index characterized the functional of the soy protein hydrolysates. The bitterness value of the soy protein hydrolysates was obtained by sensory evaluation. The results indicated that when using Alcalase for enzymeassisted aqueous extraction, the highest oil extraction rate was 91.23% and the solubility of soybean protein hydrolyzate was 91.12%. However, the bitterness value of the hydrolyzate was increased greatly which was 4, the emulsion activity index and emulsion stability index were not good. When using Flavourzyme for enzymeassisted aqueous extraction treatment, the oil extraction was 87.73% and the solubility was 87.12%. However, the bitterness of the hydrolyzates was only 1.5, thus the sensory evaluation was the best. And the hydrolyzates had the best emulsion activity index and emulsion stability index.