An α-PbO 2 layer were synthesized on the Pb-0.3%(mass proportion)Ag alloy substrates by constant current electrosynthesis from an alkaline solution, and Pb-0.3%Ag/α-PbO 2 composite inert anode materials were obtained. An electrochemical investigation of α-PbO 2 deposition process on the Pb-0.3%Ag alloy substrates, using anodic polarization technique, galvanostatic polarization technique and steady state polarization technique, has been carried out. The phase composition and surface microstructures of α-PbO 2 layers in different synthesizing times were tested by means of XRD and SEM, respectively. The experimental data have shown that the process of α-PbO 2 formation on Pb-0.3%Ag alloy substrates have several stages. The optimized conditions can be effectively improving the formation rate of α-PbO 2 and avoid the occurrence of oxygen evolution reaction. The α-PbO 2 deposition layer obtained in alkaline solution possesses compact structure, and it is composed of well developed spherical grains.