The synthesis of a new triazene reagent 1-(4-antipyrine)-3-(sulfanilic acid)-triazene (ASTA) and is proposed as a new sensitive reagent for the extractive spectrophotometric determination of Zinc(II) was established. The results showed that in the presence of micromulsion Tween-80, ASTA could reacted with Zn ( Ⅱ) to form a red stable complex of which the molar ratio of reagent︰metal was 2︰1 in Na2B4O7-NaOH medium. The maximum absorption peak of the complex was located at 520 nm with the apparent molar absorption of 1.7×105 L•mol-1•cm-1. Beers law was obeyed in the range of 0.3～5.0 μg/10 mL for Zn (Ⅱ) and the detection limit was 0.11 mg/L. Many ions did not interfere the colour reaction system due to the existence of ammonia. This method was applied to determination of Zn (Ⅱ) in water samples, and the results were in accordance with those obtained by AAS method. Recovery was in the range of 96.5～101.5 % and the RSD(n=6) was not more than 1.4%.