Abstarct: The aim of this study is the development and characterization a new optical sensor for the determination of trace amounts of zinc (ІІ) ions. The 1-(2-thiazolylazo)-2-naphtol (TAN), as a chromogenic reagent has been utilized to in the preparing the novel sensing membrane (optode) by the reagent immobilized on the triacethylcellulose membrane. The sensing mechanism is baxsed on the complex formation between Zn (ІІ) and immobilized TAN at pH=8. increase in the absorbance of the sensing film at 580 nm was spectrophotometrically measured. Under the optimum condition Zn (ІІ) can be determined in the range of 2×10-6 and 7×10-5 with a detection limit of the 9.0×10-7 mol L-1 with a response time of 12 min. The sensor can be regenerated by placing the film into a 0.010 M of hydrochloric acid solution for 20 sec for 17 times. The relative standard deviations for five replicate determination of 4×10-6, 2×10-5, and 5×10-5 mol L-1 Zn (ІІ) were 8.4%, 7.3%, and 9.2%, respectively. The sensor showed sufficient repeatability, reproducibility and operational life time of 6 weeks. The sensor was applied for determination of Zn (ІІ) in tap water, hair and oral syrup samples with satisfactory results.