Abstract:The antioxidant activities of dried fruits are abnormal in previous experiments，which might be due to the existence of sulfur dioxide.Therefore，the antioxidant activities of sulfur dioxide were analyzed by using1，1-Diphenyl-2-picrylhydrazyl （DPPH），ferric reducing antioxidant power（FARP），2，2-diamine-（3-ethyl benzothiazolin-6-sulfonic acid）diammonate （ABTS）and oxygen radical absorbance capacity（ORAC）assays，and the sulfur dioxide contents of 8 kinds of dried fruits were analyzed in this paper.The experiment results showed that sulfur dioxide exhibits some antioxidant ability，and the antioxidant ability of 1 mg sulfur dioxide is equal to that of 1 μmol Trolox-2 μmol Trolox.Additionally，there a linear correlation between sulfur dioxide concentration and antioxidant activity，and the ORAC showed the best results of antioxidant activity（R2=0.998 4）.Among the eight kinds of dried fruits，sulfur dioxide was detected in yellow raisin，wolfberry，apricot，big fig and small fig.The sulfur dioxide contents of yellow raisin and wolfberry are 1.45 g/kg DW and 0.18 g/kg DW，respectively，which are out of the national standard limit of sulfur dioxide in dried fruit.This suggests that sulfur dioxide might be one of reasons for resulted in abnormalities of antioxidant activities of some dried fruits.Therefore，the effects of sulfur dioxide should be taken into account，when samples are analyzed.