A new conductivity detector for capillary electrophoresis consisting of an electrochemical cell and a conductive meter was developed. In the cell. the microelectrode and capillary were inserted through the cell wall and fixed by screws and sealing ring. the ends of microelectrode and capillary were located by a guide with two cross holes. LOD for K+ was 1.5× 10-5 mol/L. A new conductivity detector for capillary electrophoresis consisting of an electrochemical cell and a conductive meter was developed. In the cell. The microelectrode and capillary were inserted through the cell wall and fixed by screws and sealing ring. A guide with two cross holes. LOD for K + was 1.5 x 10-5 mol / L.