Poly(vinyl chloride) (PVC) has been found to be actuated by applying dc electric field, accompanying colossal strain on the anode surface, particularly when plasticized with large amount of plasticizer [1]. We call the plasticized PVC as PVC gel for convenience in this paper. The deformation has been explained only phenomenologically. However, impedance spectroscopy revealed recently the some fundamental mechanism of the actuation, that is, the deformation depends on the dielectric nature of the materials. The colossal increase of dielectric constant was induced in the gel in the low frequency range. The dependency is strongly depends on the nature of the plasticizer and its content. The phenomena observed as electrical actuation of the PVC gels were (1) Creep deformation on the anode surface, (2) Creep induced bending motion, (3) Tacking to the anode, (4) Contractile deformation, and (5) Vibrational motion by dc electric field application. Creep deformation and the excellent transparency of the gel can be utilized for focus controllable lens. Tacking force can be applied various in combination with bending deformation. Bending actuator has been successfully applied micro-finger actuator and passed for hundreds thousands times continuous operation. In this paper, we will introduce not only the various features of the actuation, but also will get into the some detailed mechanism of the deformation.