Soy β-conglycinin-rich（7S-rich） fractions were hydrolyzed by alcalase,and the hydrolysates were investigated in terms of solubility,droplet size distribution of emulsion and heat-induced gelling properties.Moreover,the effect of the degree of hydrolysis（DH） on the functional properties of the hydrolysates was discussed.The results show that（1） the initial stage of enzymolysis,namely,the stage in the first 30min with a DH lower than 7.69%,constitutes a key stage for the formation of the functional properties of 7S-rich fractions;（2） at a DH of 4.53%,the solubility,emulsion activity and gelling property of the hydrolysates improve significantly;（3） at a DH of 4.53% and a pH value of 7.0,the solubility and elastic modulus improve by 27.3% and 158.15%,respectively,while the average droplet diameter of emulsions stabled by hydrolysates decreases to 0.936μm,which is only 4.55% of that of emulsions stabled by 7S-rich fractions;and（4） with the further increase in DH,both the emulsion activity and the gelling property show a downward trend.