We have investigated the crystallization of amorphous Y-Ba-Cu-O films with pulsed laser irradiation. The Y-Ba-Cu-O films were prepared on Si (001) substrates by pulsed laser deposition at room temperature. The microstructure and surface morphology of the films during the crystallization process were studied by x-ray diffraction and scanning electron microscopy. Micro or submicro Y-Ba-Cu-O crystalline particles can be obtained with variant laser pulses and energy densities. The particles have half-spherical or even spherical shapes on the film surfaces, and the saturated particle sizes were found to be determined by the film thickness.