The structural property and electric field response of a single perovskite PbTiO3 nanowire were investigated by means of synchrotron X-ray diffraction (XRD) with a micro X-ray beam. XRD 0-20 patterns and Raman spectra confirmed the formation of the perovskite phase of PbTiO3 by annealing the PX-phase of Pb-Ti-O nanowires at 600 degrees C. In addition, the obtained nanowires showed multi-domain/grain features. By focusing the micro X-ray beam on a single perovskite PbTiO3 nanowire, both ends of which are connected to electrodes, the lattice distortion under the electric field was observed. (C) 2010 The Japan Society of Applied Physics