Antimony doped tin oxide (ATO) films were deposited on glass substrate by magnetron sputtering using a ceramic target of 96at% SnO₂/4at% Sb₂O₃. The effects of sputtering power, pressure and post annealing on the near-infrared (NIR) blocking property of ATO films were investigated. The Uv-Vis-NIR transmission spectra and Hall Effect were measured and the microstructure of the films was analyzed with XRD and SEM. It was demonstrated that the ATO films deposited at room temperature showed relatively high transmittance in NIR region, while after annealing in nitrogen, the ATO films deposited under different sputtering powers and pressures performed obvious decrease in NIR transmittance respectively. For ATO films deposited at a sputtering power of 200W with a pressure of 1.4Pa in 10% O₂ atmosphere, the transmittance at 550nm increased from 80.9% to 85.8% and that at 1500nm decreased from 84.6% to 23.0% after annealing at 500℃ for 1 hour in nitrogen.