Transparent conductive aluminum-doped zinc oxide (AZO) films had been prepared on glass substrates by radio frequency magnetron sputtering with different sputtering powers using an ultra- high density ceramic target at 100°C Crystallinity levels, microstructures, optical and electrical properties of these thin films were systematically investigated by the scanning electron microscope, X-ray diffraction diffractometer, UV-visible spectrophotometer and four-point probe method. All the AZO thin films exhibited preferential orientation along the (0 0 2) plane with hexagonal wurtzite structure. The average transmittance of the thin films is over 86%, the highest transmittance 88.97% and the lowest resistivity 3x10-4Ω·cm are simultaneously obtained at 200W. With the sputtering power increase, the grain growth was deteriorated and the resistivity increased from 3x10-4Ω·cm to 2.5x10- 3Ω·cm. The band gaps of AZO films range from 3.81eV to 3.89eV. This article discussed some important patents related to the methods of depositing AZO thin films.