The ZrN film was prepared on the mirror stainless steel plate by using unbalanced magnetron sputtering technique. The thickness of ZrN films was controlled by changing the coating time. The L* ,a* ,b* values of the ZrN thin films with different thickness was measurea with X-rate colorimeter. The curve about the L* ,a* ,b* values of the ZrN thin films with different thickness was draw out. The color variation of the magnetron sputtering ZrN films effected by the film thickness is obtained: when film thickness is less than about 63.7 nm, with the film thickness increasing, the L* ,a* values do not change, b* values are increase by linear, and the color of the film become gold gradually; when film thickness is over about 63.7 nm, with the film thickness increasing, the chromaticity coordinates of the film has no significant change, and the color is stable gold.