The spheroidizing behavior of the lamellar Al8CeCu4 phase in the Al-14Cu-7Ce alloy annealed at elevated temperatures was investigated by microstructural observation, hardness testing and theoretical calculation. With increasing the annealing temperature, the spheroidizing process of the Al8CeCu4 phase was accelerated. The controlling element for the spheroidizing process was determined being Ce by theoretical calculation using the general rate equation. Microstructure observation indicated that the spheroidizing process of the Al8CeCu4 phase included two successive parts, i.e., the curved lamella breaking into long rods by Gibbs-Thompson effect and then the rods separating into spherical particles further by Rayleigh’s capillary induced perturbation mechanism.