Transparent conducting films ZnO have been prepared by D. C. reactive magnetron sputtering through modified S-gun in corporating Zn target inlaid with indium in proportion on its surface. Films with resistity of 1.08 × 10-3 Ωcm, transmittance of around 80% in the visible region were obtained. Conductive mechanism of indium-doped ZnO films was explained on semiconductors physios theory. Optical properties were modeled by the Drude theory of free electron from the visible region to the infrared region. The result showed that oaloiilaied yalue of optical properties agreed well wiilL experimental data.