Li-doped ZnO thin films were grown on quartz substrates by radio frequency magnetron sputtering and In-situ annealing. The structural, electrical and optical properties of Li-doped ZnO films strongly depend on the annealing oxygen pressure. XRD and AFM analysis indicate that the ZnO films possess a good crystallinity with c-axis orientation, uniform thickness and dense surface. Optical transmission spectra show a high transmittance (~85%) in the visible region. Hall measurement demonstrates that ZnO films have p-type conduction with a Hall mobility of 5.0 cm2/Vs, resistivity of 0.97Ωcm and carrier concentration of 1.60×1017cm-3 when annealing oxygen pressure is 1Pa.