The anodic oxidation of tantalum in sulfuric acid has been studied by analyzing open-circuit transients applied at intervals along galvanostatic oxidation transients. The dependence of the oxidation current density, i, on the overpotential, V, is expressable in an equation of the form i = io exp (V/Vo), where io and Vo are parameters determined from the data analysis. The parameter Vo is found to vary linearly with the potential during galvanostatic oxidation, while io depends on the applied current density. Using this equation relating current density and potential, together with a knowledge of the behavior of the parameters io and Vo, one can predict both the steady-state and transient behavior of this system. © 1969, The Electrochemical Society, Inc. All rights reserved.