【Objective】The aim of the present research was to prepare an organic iron compound, Spirulina polysaccharide iron complex (SP-Fe), evaluate its antioxidant activity and lymphocyte proliferation activities. 【Method】SP-Fe was prepared by chemically modification using chloride ferric and Spirulina polysaccharide (SP), which was characterized by fourier transform infrared (FTIR), differential scanning calorimetry (DSC), pyrolysis gravimetric analysis (TGA), X-ray diffraction (XRD) and scanning electron microscopy (SEM).【Results】The iron content (16.42?1.17%) of SP-Fe complex was obtained. By 5-axe cobweb charts, the results showed antioxidant activity of SP-Fe complex was higher than that of SP. The released iron content reached 83.64% in artificial intestinal juice for a prolonged time after arti-ficial gastric juice conditions. The lymphocytes proliferation of SP-Fe complex was increased by 44.35% comparing with that of SP at the sample concentration of 31.25μg/mL.【Conclusion】The SP-Fe complex had potent antioxidant activities in vitro assays and could be applied as a novel iron source in dietary supplements.