ABSTRACT : The electrodeposition of indium onto a copper electrode from an aqueous sulfate solution contain-ing In 3+ was studied by means of cyclic voltammetry and chronoamperometry. Reduction and oxi-dation of indium on copper were investigated by using cyclic voltammograms at different negativelimiting potentials and at different scan rates in cumulative cycles. Cyclic voltammograms indicatedthat reduction and oxidation processes of indium could involve various reactions. Chronoamper-ometry was carried out to analyze the nucleation mechanism of indium in the early stage of indiumelectrodeposition. The non-dimensional plot of the current transients at different potentials showedthat the shape of the plot depended on the applied potential. The nucleation of indium at potentialstep of − 0.6~ 0.8 V was close to progressive nucleation limited by diffusion. However the non-dimensional plot of current transients for the indium nucleation showed different behaviors fromtheoretical curves at the potential step lower than