Abstract: Method of cyclic voltammetry for static systems has been modified through its recording system in order to apply it to follow the oscillating change of concentrations of some species in a chemical oscillation reaction. In this paper, oscillation of the concentration of bromide-ion in Melonic-acid-KBrO_2-H_2SO_4-MnSO_4 systems was followed by this modified method. It was found that, for systems investigated in this paper, the bromide-ion concentrations oscillate in the range of IO~(-4) mol dm~(-3) which is 1-2 orders of magnitude higher than that observed by the bromide-ion selective electrode. A frozen-titration method for bromide-ion was also used to check the result which was found to be in agreement with that of the modified method.