An all-thin-film glass/ITO/WO3/LiAlO2/NiOx/ITO device was fabricated by magnetron sputtering for electrochromic application, in which LiAlO2 is firstly used as the ion conducting layer.All the thin films were prepared with the substrate temperature below 0 ℃.The films structure is characterized by x-ray diffraction (XRD), and morphology of the films are characterized by scanning electron microscopy (SEM).The electrochromic properties of the films and the device are measured with optical spectrophotometry.The average visible light transmittances of bleached and colored state can reach 73.4% and 32.8%, respectively, and the optical transmittance modulation can reach 40.6%.The results indicate that the LiAlO2 thin film was a suitable ion conductor for the electrochromic device, and the monolithic system such as glass/ITO/WO3/LiAlO2/NiOx/ITO has great potential to be applied in smart windows.