Abstract: Insoluble dietary fiber was extracted from white radish by acid method, the antioxidant capabilities and physicochemical properties were investigated. The results showed that, the DPPH·scavenging rate of insoluble dietary fiber was the highest（65.33%） under following conditions: using 0.1% citric acid solution as extracting solvent, the ratio of liquid to material 30∶1（mL/g）, and processing in 50 ℃ water bath for 30 min. And the extraction yield of insoluble dietary fiber was 39.72%, and it showed excellent physicochemical properties: water holding capacity 6.48 g/g, swelling capacity 4.4 mL/g, and oil holding capacity 2.12 g/g.