ZnMgBeGaO/Ag/ZnMgBeGaO multilayer structures were sputter grown and characterized in detail. Results indicated that the electrical properties of the ZnMgBeGaO films were significantly improved by inserting an Ag layer with proper thickness (~ 10 nm). Structures with thicker Ag films showed much lower optical transmission, although the electrical conductivity was further improved. It was also observed that the electrical properties of the multilayer structure were sizably improved by annealing in vacuum (~35% at 300 oC). The optimum ZnMgBeGaO(20nm)/Ag(10nm)/ZnMgBeGaO(20nm) structure exhibited an electrical resistivity of ~2.6 × 10?5 Ωcm (after annealing), energy bandgap of ~3.75 eV, and optical transmittance of 65%~ 95 % over the visible wavelength range, representing a significant improvement in characteristics versus previously reported transparent conductive materials.