Amorphous InGaZnO (a-IGZO) films were deposited on the corning eagle XG (EXG) glass substrates using magnetron sputtering method.The structure,surface morphology,electrical and optical properties of these films were investigated by X-ray diffraction (XRD),scanning electron microscopy (SEM),semiconductor parameter analyzer and spectrophotometry,respectively.The influence of oxygen flow on the electrical properties of IGZO thin films was studied,showing that increasing oxygen flow changes the resistivity with six orders of magnitude.The contact resistance of ITO/IGZO is 7.35× 10-2 Ω·cm2,which suggests that a good ohmic contact exists between In2O3:Sn (ITO) and IGZO film.