Abstract: Our objective is to extract anthocyanin from Red Raspberry by microwave assisted extraction (MAE) and study the ability of scavenging free radicals in vitro. We design the experiment by central composite design. By measuring the ability of scavenging hydroxyl free radicals, ABTS and DPPH, we can determine their antioxidant capacity. The result is that after soaking 10min, the optimal conditions for MAE were using 20:80 acid ethanol as solvent with the material ratio of 1:60(w/v), and extracting for 40s under microwave power of 600W. In this condition, the predicted content of anthocyanin is 0.055mg/g, while the true content is 0.054mg/g.