Abstract: Cross-linking reaction between polyvinyl alcohol and glutaraldehyde has been widely applied to microencapsulation and polymer modification.In this study,the cross-linking between polyvinyl alcohol and glutaraldehyde was characterized.The polyvinyl alcohol concentration is measured in the reaction spectrophotometrically.The stoichiometric ratio is determined between polyvinyl alcohol and glutaral-dehyde.The experimental results have demonstrated that the cross-linking reaction is irreversible and the stoichiometry of polyvinyl alcohol and glutaraldehyde is about 1:525.The kinetic equation has also been established for cross-linking reaction,with the polyvinyl alcohol and glutaraldehyde exhibiting a kinetic order of zero and 0.7 respectively,and the parameters have been evaluated by fitting.