Hydroxypropyl cellulose (HPC) aqueous solution has cholesteric liquid crystal phase and is colored by a selective reflection. Because the wavelength of the selective reflection depends on the kind and concentration of an additive ion, the color can be changed by applied voltage which can change a local concentration by electrophoresis. However, many tiny bubbles appear on the electrodes of the HPC liquid crystal device due to electrolysis, and the color change response is inhibited by the bubbles. In this study, the bubbles were decreased by another type of voltage application.