A memory type image display using photoelectrophoresis of TiO₂ particles was studied. Optical characteristics of images formed on the display panel were analyzed and a theoretical model if or that was presented. It was suggested by the model that the suitable applied voltage for the display is that just lower than the critical voltage for electrohydrodynamic instability. The sensitivity, the contrast, the latitude and the resolution were respectively about 10 lx , 0.83, 1.2 and 10 mm^-1 under the condition. The theoretical image characteristics given by the model was in good agreement with the observed one.