Abstract: TaAlN thin films were deposited on Al2O3 substrates by reactive DC magnetron sputtering. The content of Al doping in TaN thin films was controlled by adjusting Al/Ta area ratios of the composite target. The influences of Al/Ta area ratios on the micro-structures and the electrical properties of the samples were investigated in detail. The X-ray diffraction (XRD) results show that AlN (101) and AlN (202) phases precipitate out at 2θ of 38.5° and 65.18° in aluminum doping TaN films, respectively. With the increase of the Al/Ta area ratios, the deposition rate, resistivity and the absolute value of temperature coefficient of resistance (TCR) of the samples increase gradually. When the Al/Ta area ratio is zero, the resistivity and the absolute value of the TCR of the samples are 247.8 μΩ·cm and 12 ppm/℃, wit hr etshpee icnticvreelays.e Hoof wtheev eAr,l/Ta area ratio up to 29%, the resistivity and the absolute value of the TCR of the samples are increased to 2 560 μΩ·cm and 270 ppm/℃, respectively.