Abstract: Multi aluminum films on glass plate were selectively anodized to fabricate high density MCMD（multi-chip module deposition）substrate.The insulation property and the dielectric property of porous anodic alumina films were studied.The result shows that the cohesion between aluminum and porous alumina is good.The insulation resistance of interlayers and same layers were 10⁹Ωand 10¹¹ Ωrespectively.The dielectric constant and the dissipation factor at 1 MHz was 5.73 and 0.022.The conductive lines and vias and the insulation layers are coplanar.The interlayer vias have good electronic interconnection.The dielectric film of porous anodic alumina is suitable for MCM-D substrate fabrication.