With different laser energy outputs, a series of ZnO nanoparticles were prepared using the method of the pulse laser ablation, which were characterized by transmission electron microscope (TEM) images, photoluminescence spectra and Raman spectra. The results indicated that the size distributions and Raman spectra of ZnO nanoparticles were independent of laser energy outputs; however, with the increase of laser energy output, the photoluminescence spectra (PL) of the nanopaticles exhibited a red-shift because of the agglomeration. Finally, the mechanism of pulse laser ablation for ZnO nanoparticles was also discussed.