Transparent conducting Nb-doped ZnO(NZO) thin films were prepared by DC magnetron sputtering on glass substrate at room temperature.The effects of target-to-substrate distance on structural,morphological,optical and electrical properties of ZnO:Nb films are investigated.Experimental results show that Nb-doped ZnO thin films exhibit preferred c-axis-orientation with different target-to-substrate distances.When the target-to-substrate distance decreases,the intensity of(002) diffraction peak is enhanced.The surface of the films tends to be smooth,uniform and compact while the film thickness gradually decreases as the target-to-substrate distance increases.The lowest resistivity achieved is 6.04×10-4 Ω·cm when the target-to-substrate distance is 60 mm and the prepared film thickness is 355.4 nm.The film presents a high transmittance of 92.5% in the visible range and the optical band gap is 3.39 eV.