Chloromethyl polystyrene polymer (CMPSpolymer) has been modified with 2-carboxy-2-hydroxy5-sulfoformazyl benzene (Zincon) to be used as a new reagent for preconcentration of Cu(II) and Zn(II) ions. The modified polymer (Z–polymer) has been characterized by elemental analysis and IR spectra. Batch and column modes were operated. The newly designed polymer sorbs Cu(II) and Zn(II) quantitatively at pH 7 with flow rate of 5 ml min–1. The maximum sorption capacities for Cu(II) and Zn(II) ions were 1.26 and 1.04 mmol g–1. The preconcentration factors were 250 and 200 for Cu(II) and Zn(II) ions. The limit of detection was 4 and 5 ng ml–1 for Cu(II) and Zn(II) ions. The desorption was effective by using 5 ml of 0.1 mol l –1 HCl or HNO3 prior to detection using AAS. The modified polymer was highly ion-selective even in the presence of large concentration of electrolytes or organic media, with a preconcentration ability for Cu(II) and Zn(II) ions. The modified polymer was tested on its utility with synthetic, natural water and drug samples, showing RSD value of < 3% which reflects good accuracy and reproducibility. Keywords: Chloromethyl polystyrene polymer; preconcentration of Cu(II) and Zn(II) ions.