In this study, one-dimensional cesium tungsten bronze nanofibers with different crystalline phases have been successfully synthesized by electrospinning method followed by heat treatment. XRD analysis revealed that the effect of cesium content was significant on the crystal phase of the CsxWO3 nanofibers. The pure tungsten oxide nanofibers showed formation of a monoclinic phase of WO2.83. On the other hand, the XRD results of cesium doped tungsten oxide exhibit phase transitions from monoclinic, to a mixed phase (monoclinic/orthorhombic/hexagonal), to hexagonal and finally to cubic-pyrochlore with increasing the molar ration of Cs/W from 0.1 to 0.6. The SEM analysis depicted that the samples have a one-dimensional nanofiber structure and the fibers diameter increases by increasing Cs content. In addition, it is found that the synthesized sample with cesium to tungsten molar ratio of x = 0.66 have a hollow nanofiber structure. According to optical properties investigation, all samples exhibit a broad NIR absorption band from 600 nm to 1100 nm, indicating its potential application for light absorption and photocatalysis under any part of solar light available. (C) 2017 Elsevier B.V. All rights reserved.