3D　simulation　of　an　ERT　sensor　field　is　established　using　COMSOL　and　MATLAB　7.0　to　study　the　limitations　of　an　ERT　system＇s　sensor　field　and　determine　the　influence　of　electrode　size　and　geometry　on　the　established　field.　As　a　result　of　the　analysis,　a　pointed　electrode　array　and　a　rectangular-shaped　electrode　array　were　designed　and　their　frequency　characteristics　were　tested　by　measuring　conductance　in　milk　flows.　The　results　indicate　that　increasing　the　width　and　height　of　the　electrode　is　beneficial　to　improving　the　axial　and　radial　distribution　of　the　sensing　field.　Increasing　the　electrode　area　can　reduce　＇connection　resistance＇　and　enable　the　ERT　sensor　to　have　more　stable　frequency　characteristics　and　improve　the　SNR　of　the　ERT　system.　©　2011　ISSN　2185-2766.