This paper reports on development of a system consisting of a portable sequential injector coupled with potentiometric unit for sensing of chlorpheniramine （CPA）, based on the reaction of CPA with potassium permanganate in acidic media. Various experimental conditions affecting the potential intensity were studied and incorporated into the procedure. Under the optimum conditions, linear relationship between the CPA concentration and peak area was obtained for the concentration range of 0.1-50 ppm. The method reflects good recovery with relative standard deviation （RSD）〈 3 %. The detection limit was 0.05 ppm. The developed method was successfully applied for determination of CPA in pure form and in pharmaceutical dosage forms. The results, obtained using the method, are in accord with the results of the British pharmacopoeia method. In addition to its accuracy and precision, the method has the advantages of being simple, inexpensive and rapid.