Abstract: ZnO/Al(O)/ZnO films were prepared on polyethylene glycol terephthalate substrate by reactive magnetron sputtering and controlling oxygen flow rate during deposition of the intermediate layer. The effects of oxygen flow rate on micromorphology and surface roughness of Al(O) film and on optical and electrical properties of ZnO/Al(O)/ZnO film were studied. The results show that with increasing oxygen flow rate, the growth mode of Al on the surface of ZnO film changed from three-dimensional island-like to two-dimensional lamellar; the surface toughness of Al(O) film increased first, then decreased and then increased, and reached the lowest value at oxygen flow rate of 6.7×10^-3 cm³·s^-1. With increasing oxygen flow rate, the transmittance of ZnO/Al(O)/ZnO film increased in the range of relatively long wavelengths, the square resistance increased and the Hall mobility and carrier concentration decreased. Considering optical and electrical properties synthetically, the suitable oxygen flow rate was 6.7×10^-3 cm³·s^-1.