Abstract: The polymer gel can be described within the mixture theory based on the framework of thermodynamics.A biphasic model is proposed for the phenomenological description of chemo-mechanical interaction of the polymer gel.The finite element equations of the chemo-mechanical behavior have been derived in this paper.Two numerical examples,which include chemical loadings or mechanical loading imposed on the polymer,are simulated using the present finite element method.The results testify that the model in this paper can describe the chemo-mechanical coupling behavior of polymer gel.