For the dioxides of group- 14 elements (CO2,SiO2,GeO2 and PbO2),PbO2 is most basic in nature. Again, in oxidation state Pb in +4, which is less PbO2 stable than its +2 state because of inert pair effect. So, Pb4+ of PbO2 has a tendency to be reduced into more stable Pb2+ (PbO) showing strong oxidising nature of PbO2.