To increase the antioxidant capacities, soybean molasses were incubated with cellulase at 50℃ in Tris-HCl buffer (50mmol/L, pH value was 5.0) for 30min. The half-maximal scavenging concentrations of treated and untreated soybean molasses decreasing DPPH 50 percent (SC50) were 9.19g/L and 17.15g/L, respectively. The reducing power of cellulose-treated soybean molasses is higher than that of untreated soybean molasses at the same concentration. HPLC analysis revealed that cellulase could hydrolyze all daidzin and genistin in soybean molasses into daidzein and genistein. This may partially contribute to the enhanced antioxidant activity of soybean molasses by using cellulase.