An electrospinning process was successfully utilized to manufacture polystyrene/cellulose nanocrystal (PS/CNC) nanofibrous mats. Morphology, crystallinity, thermal behavior, as well as mechanical and hydrophobic properties of electrospun PS/CNC nanofibrous mats were investigated. Morphological analysis of the obtained nanofibrous mats demonstrated that fine nanofibers with smooth and smaller diameter could be obtained with increased CNC contents. Fourier transform infrared spectroscopy (FTIR) and X-ray photoelectron spectroscopy (XPS) results showed that PS and CNCs were physically mixed and CNCs were probably distributed on the surface of the electrospun nanofibers. The structural property e.g. crystallinity of the electrospun nanofibers was examined using wide angle X-ray diffraction (WAXD). It was indicated that crystallinity could be increased as a result of the increased addition of CNCs and aligned nanofiber orientation. Thermal properties of electrospun PS/CNC nanocomposites were enhanced by increasing CNC loading levels. The tensile strength of electrospun PS/CNC nanofibrous mats was elevated 170% by incorporating 7 wt% CNCs in PS matrix, while the ductility was decreased from 60 to 25%. The hydrophobic property could be increased to 138° when 1 wt% CNCs was incorporated.