ZnO nanorod arrays (NRAs) with different Na contents were prepared by thermal evaporation. Sodium pyrophosphate was adopted as the Na source. The Na contents in NRAs were determined by X-ray photoelectron spectra to be 0, 6.1, and 9.4 at.%. X-ray diffraction (XRD) analyses of Na-doped ZnO NRAs were performed in experiment and by first-principle calculation with the assumption of Na substitutions. A couple of typical changes were found in XRD patterns of Na-doped ZnO. The simulation results well agreed with the experimental data, which revealed that Na mainly located at the substitutional sites in Na-doped ZnO NRAs. (C) 2012 Elsevier B.V. All rights reserved.