Abstract: The differential pulse polarographic behaviour of flavin mononucleotide (FMN) and determinative conditions have been investigated. The optimum conditions for the determination of FMNare as fllows: the clectrolyte was 0.01Msodium citrate (pH5), initial potential -0.100V (vs.Ag-AgCl), final potential - 0.600V(vs·Ag -AgCl), voltage sweep rate 100mV/sec. Afair reproducibility was obtained in the above progedure and a good proportionality between the values of the peak current and FMNconcentration (1.8×10^-6-4.7×10^-5M) has been observed. The decection limit is 6.8×10^-7M. This method provides a rapid and simple way to determination of FMN.This paper also reports that the application of cyclic voltammelry to study electrode process kinetic behavior has been established. Under the experimental conditions the rate constants for electron transfer arc determined. The values of k arc in good agreement with literature's results.