Abstract: Ferric trichloride and chitooligosaccharide were used to synthesize chitooligosaccharide-Fe complex in this experiment by chemical method. The yield was 55.56%. The content of Fe was 27.60mg/g measured by atomic absorption spectrometry method. Chitooligosaccharide- Fe complex was characterized by visible ultraviolet (UV-VIS) and infrared (IR) techniques. The antioxidant activities in vitro of chitooligosaccharide-Fe complex were investigated by pyrogallol autoxidation and DPPH method. The results showed that in the setting concentration range, the antioxidant activities increased with the elevation of concentration. The antioxidant activities of chitooligosaccharide-Fe complex were better than that of chitooligosaccharide. The clearance rates of superoxide anion free radical and DPPH of 2.0mg/mL chitooligosaccharide-Fe complex were 59.84% and 65.76%.