Rare earth element La-doped ZnO polycrystalline films are prepared on Pt/Ti/SiO(2)/Si substrate and p-Si substrate by chemical solution deposition (CSD) method. High R(OFF)/R(ON) ratios, low operation voltages within 150 switching cycles of test and long retention measurement are obtained, which indicate that the two different structure devices exhibit reversible, controllable and remarkable reliability unipolar resistive switching (RS) behaviors. The RS mechanism is related to the different substrate of the samples. The filament theory and the interface effect are suggested to be responsible for the RS phenomenon for the Pt/Ti/SiO(2)/Si substrate and p-Si substrate, respectively. (C) 2011 Elsevier Ltd. All rights reserved.