Microwave assisted enzymatic digestion (MAED) was investigated for extraction of soybean antioxidant peptides (SAP) with maximised antioxidant activity using response surface methodology (RSM) coupled with an one-factor-at-a-time (OFAT) design.The hydroxyl radical (·OH), DPPH radical, superoxide anion radical and ABTS radical scavenging were used to evaluate the antioxidant activity.The MAED processing parameters were microwave time 31 min, microwave temperature 56℃, pH value 8.09, [E/S] 5∶100, [S] 50 mg/mL, microwave power 500 W.Under the condition, MAED-500W sample was more efficient for greater antioxidant activity than MAED-0W sample.Fourier Transform Infrared (FT-IR) spectroscopy was used to analyze the changes of functional groups, comparing these results with the IR-absorption data the majority of stretching vibrations and bend can be identified, the amide band was relatively prominent in MAED-500W, while, the MAED-0W were not displayed the δ as (R-CH2-N), vs (C-N), vs (-COO-) and amides Ⅲ band.