The differential pulse polarographic behavior and quantitation of chlorophylls have been investigated. The detection limit is 2.4 X lop7 M. The kinetics of the photolytic reaction of chlorophylls has been explored. Some kinetic parameters of the reaction system and the possibilities of a path for the photolytic reaction of chlorophylls have been measured and established. This reaction shows zero order kinetics with a rate constant of 3.3 x mole dm-3 -hr-'; with the help of the Arrnhenius relation, the activation energies of this reaction were determined. The method was successfully applied to the determination of chlorophylls in toothpaste and several kinds of green leaves.