Abstarct: In this study a simple and sensitive spectrophotometric method for simultaneouse determination of copper (II) and nickel (II) is proposed. This method is baxsed on the complex formation of copper (II) and nickel (II) with 1-Phenyl-1,2-Propandione-2-Oxime-Thiosemicabazone (PPDOT) in the presence of 1-Cetyl Pyridiniom Chloride. All effective parameters on the sensitivity of the method were optimized. Calibration (24 sample) and prediction (10 sample) data set prepared by measuring the absorbance of binary mixture of copper (II) and nickel (II) in the concentration ranges of 0.1-8.0 μgml- for copper (II) and 0.05-6.0 μgml- for nickel (II), respectively. The result obtained by applying partial least squares method baxsed on the singular value decomposition was used for preprocessing of absorbance data. The obtained results by applying partial least squares with and without mean centering of ratio spectrum were ststistically compared. The 3 Detection limits were 0.10 and 0.040 μgml- copper (II) and nickel (II), respectively. The relative standard deviations for five replicate determinations of 2.0 and 4.0 μgml-1 of copper (II) were 4.8 and 2.1 and for five replicate determinations of 2.5 and 3.5 μgml-1 nickel (II) were 0.99 and 1.4, respectively. The method has been applied to the simultaneouse determination of copper (II) and nickel (II) in tap water, spring water and alloy samples with satisfactory results (Recovery 94- 103% for copper (II) and 101- 108% for nickel (II)). In this study, N, N - Bis (naphtiliden imino) diethyltriamin bonded on polystyrene has been used as a new chelating sorbent for the on–line preconcentration and determination of Cu )II( by flame atomic absorption spectrometry using a flow injection manifold. Copper (II) can be quantitatively retained on adsorbent filled in a minicolumn at pH=7.0. The elution of copper with HCl 2.0 M from the sorbent is quantitative. The effect of various chemical and instrumental variables on the preconcentration and determination of copper (II) has been investigated. Under the optimum conditions, for 10 ml of sample solution the calibration graf was linear in the range of 0.0020-0.044. The 3 limit of detections were 1.41 and 0.66 using 10 and 25 ml of sample solution, respectively. A preconcentration factor of 80 can be achieved for 10 ml of sample solution. The relation standard deviations for 10 replicate determination of 0.012 and 0.030 μgml-1 of copper (II) were 0.013 and 0.031 respectively. The method has been applied to the determinate of copper in tap water, spring water and sodium chloride solution with satisfactory results (Recovery 90- 110%).