Abstract: The redox reaction between rhodamine 6G and nitrite with KBr as the catalyst discolored rhodamine 6G in the medium of HCl,and the absorbence at 527 nm decreased obviously.There was a good linear relationship between the A value and the concentration of sodium nitrate in the range of 0.05～1.5 mg/L.The correlation coefficient was 0.999 3 and the apparent molar absorptivity was 1.09×105 L·mol-1·cm-1.The recovery was in the range of 99.4%～104.2%.The method has been applied for the determination of trace nitrite in water samples with satisfactory results