The　human　channel　transmission　characteristics　of　intra-body　communication　of　implantable　medical　sensors　are　studied.　A　quasi-static　field　model　of　intra-body　communication　of　implantable　medical　sensors　is　established　using　finite　element　method.　An　experiment　platform　was　designed,　which　is　used　to　verify　the　correctness　of　the　model.　The　electrical　potential　gains　are　calculated　as　the　intra-body　electrical　signal　transmits　along　axial　and　radial　directions　when　the　model　conductivity　has　isotropic　and　anisotropic　characteristics,　respectively.　The　results　show　that　the　intra-body　communication　signal　attenuates　obviously　along　the　axial　direction　in　the　quasi-static　frequency　band,　and　the　signal　transmits　stably　along　the　radial　direction.　And　the　influence　of　frequency　variation　on　signal　gain　is　small;　moreover,　the　signal　gain　for　the　anisotropic　conductivity　is　obviously　larger　than　that　for　the　isotropic　situation.　The　signal　gains　for　intra-body　communication　and　radio　communication　are　compared,　and　the　signal　gain　for　intra-body　communication　is　superior.