Er doped ZnO thin films were grown on Si substrates using SiO2 buffer layer by pulsed laser deposition (PLD) method. The obtained films crystallize well and show high c-axis orientation. The Er content was evidently detected by the energy dispersive X-ray spectroscopy (EDS). Upon annealing in O2 ambience at different temperatures, the films show different photoluminescence properties at 1.54 μm. The samples annealed at 700 and 850 ℃ show intense photoluminescence peaks which enhance with the annealing temperature, while no obvious luminescence peaks are observed for the as-grown samples or annealed at 500 ℃. The possible mechanism was discussed. Er doped ZnO thin films were grown on Si substrates using SiO2 buffer layer by pulsed laser deposition (PLD) method. The Er content was evidently detected by the energy dispersive X-ray spectroscopy (EDS). Upon Annealing in O2 ambience at different temperatures, the films show different photoluminescence properties at 1.54 μm. The samples annealed at 700 and 850 ° C show intense photoluminescence peaks which enhance with the annealing temperature, while no obvious luminescence peaks are observed for the as-grown samples or annealed at 500 ° C. The possible mechanism was discussed.