Prior to investigate the influences of degree of crosslinking on the hydrophilicity and mechanical strength of polyvinyl alcohol(PVA) membrane, the kinetics of crosslinking of PVA membrane with glutaraldehyde was examined. The reaction variables were temperature, hydroxyl group concentration of PVA membrane, and concentrations of glutaraldehyde and sulfuric acid in crosslinking solution. The overall reaction rate of crosslinking was suggested, which agrees well with the experimental results. The crosslinking reaction is approximately first order with respect to the concentration of hydroxyl group of PVA membrane, of glutaraldehyde, and of sulfuric acid. The activation energy was estimated to be about 5.77kcal/mol. It was also found that the degree of crosslinking of PVA membrane can be easily changed by controlling the reaction variables.