X-ray diffraction, infrared (IR), Raman spectroscopy and scanning electron microscope techniques have been used to investigate the microstructural properties of the glass materials. In this work, a new type of tellurite based optical glasses with TeO2/Nb2O5/TiO2 for different xNb2O5 (x = 5, 10, 15, and 20 mol.%) glass compositions at constant 5 mol.% TiO2 ratio were prepared. The effect of Nb2O5 contents on the structural unit of (95-x)TeO2 (x)Nb2O55TiO2 glass network, and the intensity ratios of the Raman peaks were investigated. The results indicate that for di-erent Nb2O5 content 5 to 20 mol.% in the glass system, three vibrational peaks around 650, 800, and 920 cm-1 which correspond to the structural bonding of the glass were observed in the range of 500-2000 cm-1 for the IR spectra. Furthermore, from the Raman results a structural evolution was determined with the number of structural units such as [NbO6]7, TeO3+1 (polyhedra), TeO4 (trigonal bipyramids), TeO3 (trigonal pyramids) or TeO3+1 (polyhedra), and [NbO4]3- for this ternary glass system.