Abstract: In order to obtain the characteristics of the extraction rate,antioxidant activity and chemical composition of blueberry anthocyanins in the ultrasonic assisted extraction,Box-Behnken design,and antioxidant activity test in vitro and HPLC-ESI-MS analysis were employed. The results showed that there were differences in the most significant affecting factors and optimal conditions between the extraction rate and the DPPH scavenging rate of blueberry anthocyanins. The ultrasonic temperature and the ultrasonic power were the most significant factors affecting the extraction rate of blueberry anthocyanins,while the ultrasonic time was the most significant factors affecting the DPPH scavenging rate of blueberry anthocyanins. The optimal conditions for the extraction rate of blueberry anthocyanins were ultrasonic temperature 39℃,ultrasonic power 490 W,ultrasonic p H3.5 and ultrasonic time 45 min,while for the DPPH scavenging rate of blueberry anthocyanins were ultrasonic temperature45℃,ultrasonic power 450 W,ultrasonic p H3.1 and ultrasonic time 37 min. The results of HPLC-ESI-MS analysis showed that 11 anthocyanins from blueberry belonged to anthocyanin glycosides and had the similar chemical composition obtained by both the classic extraction and ultrasound-assisted extraction.