Chitosan-polyvinyl acetate (CHI-PVA) blends were prepared throughout copolymerization reaction. Chitosan (CHI) as a hydrophilic molecule was added to modify the blend surface of polyvinyl acetate (PVA). The sorption effects of CHI-PVA blends were studied in the presence of binary feed mixture of methanol–water (MW). The obtained blends were investigated by Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), microscopic analysis and conductivity measurements to investigate the chemical structure, crystallinity, surface morphology and electric property, respectively. Effect of water content on the swelling performance of CHI-PVA blends based on (methanol/water) ratio was discussed. CHI-PVA complexes show high swelling performance with 20% CHI based blends from 50% water content in methanol–water mixture.