Flow visualizations using laser sheet were performed to investigate the corona wind flow interactions in the one-wire and two-wire type electrostatic precipitators. The corona wind generated by corona discharge was not negligible, and strong flow interactions took place owing to the induced circulatory cells. In the case of two-wire type, if upstream discharge voltage was relatively higher than downstream discharge voltage, the effect of upstream corona wind was reduced. Employing one-wire type electrostatic precipitator, the particle collection efficiency as function of primary mean velocity and applied voltage was determined for different particle sizes. Also, the distributions of the streamwise relative deposition rates were measured for particle sizes, primary mean velocities and applied voltages. As the applied voltage increases, the reduction rate of the total collection efficiency becomes smaller due to the increase of primary mean velocity.