SummaryThis work is concerned with modification of wheat bran arabinoxylans by ultrasound irradiation. The average molecular weights of arabinoxylans ranging from 580 000 to 800 000 kDa were yielded by regulating ultrasonic powder (120–480 W) and treat time (15–45 min). The phenolic compounds increased after ultrasound treatment, and arabinose‐to‐xylose ratios ranged between 0.55 and 0.67. FTIR spectroscopy revealed that the major chemical composition of arabinoxylans was unchanged. The maximum storage modulus decreased with the extension of ultrasonic treatment time. The antioxidant capacity test showed that the EC50 values decreased and the values from the ferric reducing antioxidant power decreased after ultrasound treatment. The results suggested that ultrasound is an effective method for the modification of arabinoxylans.