This paper presents characteristics of CrOx thin-film, which were deposited on $Al_2$O$_3$ wafer by DC reactive magnetron sputtering in an argon-oxide atmosphere for high temperature applications. The present paper deals with a study of the technological characteristics of thin film resistors to provide a control in obtaining temperature coefficients of resistance of given value. The optimized condition of CrOx thin-film were thickness range of 2500 $AA$ and annealing condition(350 $^{circ}C$, 1 hr) in oxide partial pressure(3.5${ imes}$10$^{-4}$ torr). Under optimum conditions, the CrOx thin-films is obtained a high resistivity, p=340 $mu$Ωcm, a low temperature coefficient of resistance, TCR=-55 ppm/$^{circ}C$. The CrOx thin films resistors which were fabricated in this paper had excellent characteristics as high precision resistors.