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.