Abstract: The effect of ultrasonic treatment on emulsifying properties of mung bean protein isolates was studied,the impact of different ultrasonic power,ultrasonic time,substrate protein concentration on emulsifying properties of mung bean protein isolates were analyzed. Response surface analysis was applied to optimize the emulsifying ability of mung bean protein isolates modified by ultrasound treatment. The results showed that the optimal reaction conditions of improving mung bean protein isolates emulsification were concluded as follows:ultrasonic power was 410 W,ultrasonic time was 10.5 min,protein concentration of substrate was 11.5%. Under the optimal conditions,the EAI was 35.01 m2/g.