Abstract: Whole-wheat flour was used as material to produce fresh noodles.The experiment was designed to understand the process and the mechanism of darkening and attempt to inhibit browning by using combination of ultrasound and antioxidants.Results showed that there were three stages in the process of darkening in 24 hours.PPO enzymatic reaction was one of major factors influencing darkening in whole-wheat fresh noodles.The combined treatment with ultrasound and antioxidant was an effective method to reduce PPO activity and inhibit darkening process in whole-wheat fresh noodles, ultrasonic treatment in 2min showed no significant effect on the content of minerals in whole-wheat flour in this experiment (p>0.05) .