Electrochemical behavior of alpha- and beta-PbO2 have been studied using all solid state batteries. The samples which have been used to compare the kinetic parameters of the reduction reaction were prepared by the electrochemical method. Hydrogen uranyl phosphate (KUP), has been used as an electrolyte, at room temperature to determine the diffision coefficient of H+ in PbO2. The values of D-H+ calculated for alpha- and beta-PbO2 are 9.6 X 10-(10) and 2.2 X 10(-9) respectively. The beta-PbO2 seems to be much more better protonic conductor than the a phase. Using the slow scan voltammetry, beta-PbO2 shows a reduction peak at 1.94 V versus Zn. In the case of alpha-PbO2, however, a similar peak is observed at 2.02 V versus Zn.