Effects of anodization voltage on frequency characteristics of anodic oxide films on tantalum were analyzed based on the following impedance equatious : (equation omitted) Here $R_{f}$, $C_{f}$ and tan $delta$$_{f}$ are equivalent series resistance in ohm, equivalent Belies capacitance in farad and dielectric loss, of anodic oxide films respectively Parameters P, $ au$$_{ο}$, $ au$$_{omega}$, and Co are defined as follows: P=(d-w)/w, $ au$$_{ο}$=$textsc{k}$$ ho$$_{ο}$, $ au$$_{omega}$=$textsc{k}$$ ho$$_{omega}$, $C_{ο}$=$textsc{k}$A/d where d is the thickness of oxide film, $omega$ is the diffusion layer thickness. $ ho$$_{ο}$ is the resistivity of oxide film at the interface of metal and the oxide, $ ho$$_{omega}$ is the resistivity of oxide film at intrinsic region and A is the area of the film and $textsc{k}$=0.0885$ imes$10$^{-12}$ $ imes$dielectric constant, (in farad/cm). It was shown that dielectric loss and frequency dependence of equivalent series capacitance decrease as anodization voltage increases. This is a consequence of the fact that the thickness of diffusion layer increases a little with increasing anodization voltage whereas the total oxide thickness is proportional to the anodization voltage. The ngative deviation of measured values from tile relation, tan $delta$$_{f}$=0.682 $Delta$ $C_{f}$, was also discussed based on the Impedance equations given above. Here $Delta$ $C_{f}$ is the change in capacitance between 0.1 and 1 KHZ.KHZ.Z.