TiNi alloy thin films, whose properties are very sensitive to the composition, were prepared using a dc sputter deposition technique. Effects of major deposition parameters on the resulting thin film properties were investigated. The atomic percent of Ti was found to increase with increasing working distance or pressure. The deposition rate was found to increase with the dc power but decrease with the working distance and pressure. The activation energy was also determined and compared to that of bulk TiNi alloys.