With　the　development　of　new　materials,　the　study　of　the　interaction　of　multi-physical　fields　is　more　and　more　important.　Many　experiments　have　shown　that　chemo-mechanical　coupling　exists　in　a　lot　of　smart　materials.　In　this　paper,　a　theoretical　model　is　proposed　for　the　uniaxial　strain　state　of　chemo-mechanical　materials.　It　is　assumed　that　the　smart　material　is　an　isotropic　continuum.　Based　on　the　coupled　governing　equations,　the　displacement　function　and　concentration　function　are　derived　and　then　the　stress　and　chemical　potential　are　obtained.　This　study　not　only　reveals　the　mechanism　of　chemo-mechanics,　but　also　provides　a　foundation　to　the　numerical　simulation.