Abstract: Physical cross-linking polyvinyl alcohol (PVA) gels were prepared by repetitive freezing and thawing processes. Mechanical properties and hydrogen bonding interactions in the gel were studied by Hakee RS300 rheometer. It was observed that, firstly, the shear modulus, tensile strength and physical cross-linking densities of gels were increased with the increase of concentration of PVA; secondly, at the same concentration, the shear modulus and physical cross-linking densities of PVA hydrogels were higher than that of PVA/DMSO gels, while the activation energies of hydrogen bonding dissociation of PVA hydrogels was lower than that of PVA/DMSO gels.