FeTiN films with good soft magnetic properties were prepared on Si and NaCl single-crystal substrates by facing-targets sputtering (FTS). The effects of Ti addition on the structural and magnetic properties of Fe - N films were investigated. Ti has been found effective in improving the soft magnetic properties as well as the thermal stability of FeN films. For the films containing 5 - 12 at.% Ti prepared under sputtering conditions of = 0.04 - 0.07 Pa, a substrate temperature of , and a sputtering rate of , the following properties are observed: very high saturation magnetization (2.3 - 2.5 T), low coercivity (160 - 240 ), and high relative permeability (3000 - 3500 at 1 MHz). The thermal stability of these films was also found to be good, e.g. was less than and was higher than 2.3 T for the films annealed up to . The crystal structures of the FeTiN films were examined with an x-ray diffractometer and a transmission electron microscope. Ti addition affects the formation of magnetic iron nitride phases and makes the crystallites small. The fine-grained Fe - N phase, together with finely dispersed TiN precipitates, is considered to be one of the main factors responsible for the good magnetic properties and thermal stability.