Soybean protein concentrate and soybean protein isolate were both limited hydrolysed with neutrase and trypsin respectively. SDS-PAGE was employed to analyse protein degradation in the hydrolysed soybean protein products. The relationship between hydrolysis pattern and the functional properties of the hydrolysed soybean protein products, such as emulsion property and oil absorption, were investigated. The emulsifying activity index, emulsion stability and oil absorption capacity of eight hydrolysed soybean protein products with the degree of hydrolysis (DH) of 1% or 2% were detected. The experimental data indicate that the emulsifying property and oil absorption capacity correlate with the protease used or the DH. For soybean protein concentrate, hydrolysis with neutrase or trypsin improves its emulsifying property and oil absorption capacity, and hydrolysis with trypsin to the DH of 1% gains the optimal emulsifying property and oil absorption capacity. At the same time, hydrolysis with neutrase or trypsin improves the emulsifying activity index of soybean protein isolate, but reduces the oil absorption capacity, and hydrolysed soybean protein isolate with trypsin to a DH of 1% has the optimal emulsion property.