With the aim to optimize the technology parameter of subcritical water extracting protein from rice bran, the single factor and orthogonal experiments were conducted by taking protein yield as index, and the function characteristics of protein from rice bran were studied. The results were as follows: the ratio of protein in the extracts was 55.9% at 8.0MPa, pH value 9.0, 200℃ for 25min with the liquid-solid ratio of 15mL/g, the emulsion activity index of rice bran protein was 119.8mL/g, and the emulsion stability indicator was 81.3min; the foamability and the stability of foam were 71.5% and 37.4% respectively; the water/oil absorption and the solubility were 5.6%, 3.7% and 68.4% respectively. The extract time and the protein yield of rice bran extracted by the methods of alkaline water and ultrasonic assisted alkaline water were 120min, 35.6%, and 30min, 48.1% respectively. Compared with the previous two methods, subcritical water extracting protein from rice bran has obvious advantage in saving time and extraction ratio.