The fine structure of poly(vinylidene fluoride) (PVDF) nanofiber prepared by electrospray deposition (ESD) has been investigated by wide angle X-ray diffraction (WAXD) and infrared spectroscopy (IR). The beta-phase crystal was dominant in the crystalline region. The degree of crystallinity of 0.54 for the nanofiber, determined by Ruland's method, was almost identical to that for a melt pressed sheet of PVDF. The disorder parameter k was 4, which is significantly smaller than the value of 6 for the melt pressed sheet of PVDF. Molecular orientation along the fiber axis was observed by the polarized infrared spectra of the uniaxially aligned nanofiber. These results suggest that the PVDF nanofiber possesses a fiber structure which is by no means inferior to that of practical fibers. (C) 2008 Wiley Periodicals, Inc.