The cyclone dust collector features a simple construction and low initial cost. It is suitable for collecting particulates with a diameter larger than 5 to 10hm in flue gas from industrial boilers. In this work, experimental investigations were made to improve the performance of a cyclone dust collector, especially for collecting micron and sub-micron particulates from gas stream by adding a high-voltage electrostatic field in the cyclone body. Effects of the gas-stream inlet velocity at the entrance of cyclone and the imposed voltage were investigated in order to find the optimum operating conditions.