The foaming property of egg white protein is widely used in bakery food.In order to improve the foaming property of egg white liquid,high field intensity ultrasound (20 kHz) with different ultrasonic power (120,240 W) and ultrasonic time (1,5,10,20,30 min) was set to modify the egg white protein.It was found that the foaming ability of egg white was the best (266.7%) when treated with 120 W ultrasound for 20 min,which was 6.9 times of that of untreated egg white.Ultrasonic treatment significantly reduced the viscosity,surface tension and particle size of the egg white (P < 0.05),which made the protein molecules more easily adsorbed to the gas-liquid interface for unfolding and rearrangement.The results of zeta potential indicated that the negative charge on the protein surface was significantly decreased at 120 W for 20 min compared with untreated egg white (reduced from -14.47 to -8.16 mV,P < 0.05).The rheology results showed that the protein membrane of egg white at the interface was always dominated by elasticity,showing the properties of viscoelastic solid,and the ultrasonic treatment didn't change its fluid state,showing a pseudoplastic fluid state all the time.