A novel, high performance wide-bore electrophoresis (WBE) system with inner cooling has been developed. By introducing the mode of shell and tube heat exchanger into this system to remove Joule heat generated during electrophoresis, it is feasible to extend the conventional capillary electrophoresis tube into wide bore (> 1.0 mm ID) diameter. The wider tube allows loading larger volume of sample with improved detection limit. Several separations of model compounds were achieved with relatively satisfactory performance on this device preliminarily. Further work is undergoing.