In this study, the polymer blend technique was used to improve the amorphous phases of two semi-crystalline polymers. Series of polymer blend films based on polyvinyl alcohol (PVA) and Chitosan (CS) with different compounds were prepared using solution cast technique. The structural characterization of the prepared pure PVA, pure CS, and their blend films was investigated using X-ray diffraction (XRD) technique. The XRD studies indicated that both PVA and CS polymer films are semi-crystalline in nature, due to intermolecular and intramolecular interaction of different units of polymer chains, through the hydrogen bonding between the polymer backbone chains. The XRD patterns for PVA:CS blend films reveal the distortion of the alignment of the molecular chains of both polymers, the lowest degree of crystallinity was obtained for PVA:CS polymer blend film with a weight ratio of 25:75. Accordingly, this composition is the optimal candidate for the preparation of the solid polymer electrolyte, due to the reduction in the crystallinity and the polar nature of polymer components.