The phase transformation kinetics in electrodeposited Cu-Cd alloys has been investigated by the application of the ALSV technique. By the analysis of the charge under the corresponding ALSV peaks it is shown that a lot of free Cd remains after phase transformation, while all Cu is found to crystallize into two intermetallic compounds, CuCd3 and Cu5Cd8. A solid State reaction kinetic has been analyzed by the Johnson and Mehl equation for heterogeneous reactions. It is found that the nucleation process is slow and highly dependent on the alloy thickness, reflecting the catalytic effect of the substrate.