A novel recombinant polysaccharide (RP) based on polysaccharide-disaccharide was synthesized from oligo-chitosan (oligo-CS) and reducing lactose using Maillard reaction with the yield of 85.1%. Chemical structure and thermal stability of RP was characterized by Fourier transform infrared spectrum (FT-IR), solid-state nuclear magnetic resonance spectroscopy (CP/MAS (13)C-NMR), and thermo gravimetric analysis (TGA). The anti-oxidant activity of RP was preliminarily investigated by its scavenging effect on 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical. Biodegradability of RP was also examined by the observation of growth status of Aspergillus niger colony. It was demonstrated that RP achieved excellent radical-scavenging efficiency (>80%) at high concentrations of DPPH and its scavenging ability was superior to that of CS, suggesting that anti-oxidant property of CS was remarkably promoted by chemical modification with reducing lactose via Maillard reaction. And biodegradation test revealed that RP had better biodegradability than CS.