Action of gelatin hydrogel crosslinked with glutaraldehyde under dc electric field of high voltage was studied. The experimental results show that the hydrogel can be driven by dc electric field of high voltage in the medium of silicone oil, and the action of the hydrogel is composed of rotation and translation. There is a low critical applied voltage of 0.5 kV, below which the action of the hydrogel may not be observed. The motion velocity and angle of the rotation of gelatin hydrogel are influenced by the electric field intensity. Because silicone oil is very stable and hard to electrolyze in electric field, gas formation associated with the electrolysis of water, which is inevitable and disadvantageous in conventional system of electric-stimulus-response hydrogel, would not happen. Our work has provided a novel kind of electrodriven methods for hydrogels. (c) 2006 Wiley Periodicals, Inc.