Abstract: Based on the catalytic effect of trace amounts of nitrite on the oxidation de-coloration reaction between potassium bromate and PAN in dilute phosphoric acid medium,a new method for the determination of trace amounts of nitrite was established.The linear rang for nitrite is 0.2-8.0 μg/25 mL,and the detection limit is 5.7 μg·L-1.The proposed method has been applied to the determination of traces of nitrite in water and fruit samples giving RSD′s less than 2.5%,and recoveries in the range of 101%-104%.