The physicochemical and emulsifying properties of pork myobrillar protein (MP) solution treated by ultrasound power: 0, 80, 140, 180 and 200 W were examined. Compared with MP without ultrasonic treatment, with the increase of ultrasonic power, d_{4, 3} of MP decreased, while solubility, absolute value of the zeta potential, emulsifying activity and emulsion stability were significantly increased. Meanwhile 180 W was the optimum ultrasound power to obtain the highest emulsifying activity index (EAI) and emulsion stability index (ESI). The increase of emulsion stability was related to increased zeta potential and reduced average particle size. Optical microscopy observation proved that emulsions possessed relatively small oil droplets. Correlation analysis showed that ultrasound power was significantly negatively correlated with d_4,3(P≤0.01), and positively correlated with solubility, absolute value of the zeta potential, emulsifying activity and emulsion stability(P≤0.05).