The surface microstructures of spherical Pt single crystals are studied by reflection electron microscopy, and the defect configurations in the crystals are also analysed. Dislocations and low angle grain boundaries appear in the initial stage of the solidification of liquid drops. In the following annealing, the dislocation density decreases and single crystals are formed owing to the movements of dislocations in the grains to the subgrain boundaries, and those in the subgrain boundaries to the surfaces of crystals.