H, Ga-codoped ZnO (HGZO) thin films were prepared by RF magnetron sputtering in Ar+H2ambient at room temperature.The effects of H2 flow on structural, chemical, electrical and optical characteristics of GZO film were investigated.The XRD analysis indicates that HGZO film had a polycrystalline hexagonal wurtzite structure and consisted of crystallites with preferred orientation along the c axis and adding H2 results in the textured surface structure and the result of XPS analysis showed that Ga has been incorporated and most of Ga substituted for Zn in ZnO and H2 have a influence on the stoichiometry of the HGZO films.The characteristics of HGZO film prepared at RT can be markedly optimized by controlling Ar + H2 ambient.In the current work, the resistivity of 3.89× 10-4Ωcm and the average transmittance of 90.7% in the visible range were obtained with the optimal H2 flow of 1.5sccm.