Ag/GZO/ZnO/Pt structure resistive switching devices were fabricated by radio frequency (RF) magnetron sputtering, in which ZnO was used as a buffer layer. These devices have large ratio of high resistance state (HRS) to low resistance state (LRS), which is 2 x 10(3). The storage time measurement indicates that these devices have an excellent data retention characteristic. Moreover, the operation voltages are very low, which is 0.4V (ON state) and -0.35/-0.55 V (OFF state). The electroforming process in initial state was not needed, and multistep reset process was found. (C) 2012 Elsevier B.V. All rights reserved.