Glasses based on the system of Y2O3-BaO-Nb2O5-B2O3, corresponding to the pseudo-binary 64Ba1−xY2x/3Nb2O6-36B2O3 with x=0.1–0.5, were prepared, and their thermal properties, electronic polarizabilities, optical basicities, and crystallization behavior were clarified. The glasses showed the glass transition temperature of 602–610°C, crystallization peak temperature of 686–676°C, and refractive index of 1.967–2.007. All the glasses showed the bulk crystallization behavior, providing Ba1−xY2x/3Nb2O6 nanocrystals with a tetragonal tungsten bronze structure. It was found from high resolution transmission electron microscope observations that the morphology of Ba1−xY2x/3Nb2O6 nanocrystals is ellipsoidal and their average particle size is in the range of 20–40nm. The glass-ceramics with Ba1−xY2x/3Nb2O6 nanocrystals showed high dielectric constants (frequency: 1kHz) of ~90 at room temperature and a ferroelectric nature. Highly oriented Ba1−xY2x/3Nb2O6 crystal lines were patterned by laser (continuous wave Yb:YVO4 fiber laser with a wavelength of 1080nm) irradiation with the condition of a laser power of 1.9W and a laser scanning speed of 4μm/s and with the laser focal position of 20μm beneath from the surface in 2NiO-1.1Y2O3-29.8BaO-33.1Nb2O5-36B2O3 glass.