Abstract: Ga₂O₃ thin Films have been fabricated using 355nm pulsed laser deposition. XRD and AFM measurements showed that the films mainly consist of nanosized polycrystalline β-monoclinic Ga₂O₃. Photoluminescence （PL） spectra of the thin films deposited at various oxygen pressure were measured. With the increase of oxygen pressure, the PL intensity increased along with the wavelength red-shifts of the emission band, which may be due to the increase of the grain size. CeO₂ dopant can enhance the PL intensity and influence the PL spectrum obviously. Additionally, the time-resolved emission spectrometry was used to characterize the ablated species generated from the laser ablation of Ga₂O₃. Gallium oxide species in the plume increased with increasing the oxygen pressure and the laser fluence.