Niobium oxide thin films were successfully synthesized starting from niobate nanosheets. The microstructure of as-prepared nanosheets was observed by TEM. The morphology of niobate thin films was investigated by SEM. The phase structure was determined by XRD. The transmittance spectra of as-obtained niobium oxide thin films were measured, and the optical properties were studied. The influences of different thickness on optical properties were also analyzed. As-prepared niobium thin films were treated by being heated at different temperature. The effects of soaking temperature on the structure and optical properties of niobium oxide thin films were discussed in detail.