Abstract: The anthocyanin of strawberry fruits was extracted by ultrasonic -assisted method in this paper. Response surface methodology (RSM) was proposed to optimize the extraction process. The experimental factors and levels were chosen according to the results of single factor experiment. The significance and interaction of factors were carried out using response surface method (4 factors and 3 levels) in terms of Box -Behnken. Results showed that solid -liquid ratio was the most significant factor affecting the extraction rate, According to the result of optimization, strawberry anthocyanin should be extracted with solid-liquid ratio 1∶16 under 90W ultrasonic power for 14min at the temperature of 44℃. Under this condition, the actual extracted amount of anthocyanin was 1657.3μg/g, which was consistent to the theoretical value (1737.3μg/g) .