Abstract: This study was to improve the antioxidant properties of chitosan by modify it with Maillard reaction. The DPPH free radical scavenging activity, reducing power and iron ion chelating ability of modified chitosan Maillard reaction products of (MRPs) were measured to determine the influences of such reaction conditions as different viscosity and concentrations of chitosan, different glucose concentration, pH and temperature on the antioxidant properties in vitro of MRPs. Results showed that the antioxidant properties in vitro of MRPs (products of chitosan modified by Maillard reaction) had been improved significantly (p<0.05) , and the DPPH free radical scavenging activity and reducing power of MRPs were positively correlated to the viscosity and concentration of chitosan, glucose contration and reaction temperature (p<0.05) . The MRPs of Low, medium viscosity of modified chitosan only differed in reduing power (p<0.05) . The iron ion chelation rate of 1% of the low, medium viscosity chitosan MRPs were increased by 34.41% and 24.5%, respectively. The pH3.6～5.4 value had a complicated influence on the antioxidant properties of chitosan MRPs.