Piezoelectric nanostructures have recently attracted attention because of their potentials for nanoscale sensing and energy scavenging. Here we present the fabrication and characterization of novel piezoelectric 0.65Pb(Mg1/3Nb2/3)O-3-0.35PbTiO(3) (PMN-PT) nanofibers. PMN-PT nanofibers were fabricated by an electrospinning process combined with subsequent high temperature treatment. The diameter of the nanofibers ranged from 148 nm to 216 nm. Well aligned nanofiber arrays were obtained using an electric field assisted method. A theoretical model was given for measuring piezoelectric properties of nanofibers using Piezoresponse Force Microscopy (PFM). The electromechanical coupling coefficient (d(33)) of single PMN-PT nanofibers was measured and a value of 50 +/- 2 pm/V was obtained. The excellent properties of these nanofibers may enable the development of novel piezoelectric nanosensors and nanogerators for sensing and energy harvesting applications. (C) 2012 Elsevier Ltd. All rights reserved.