In this study, macroscopic polyamide 66 (PA66) nanofiber bundles were successfully electrospun using two electrode pins as collector. One of the pins can rotate with a speed of 300 rpm. Scanning electron microscope, tensile test, wide-angle X-ray diffraction and differential scanning calorimetry were employed to characterize the arrangement of electrospun nanofibers in bundle, tensile property and microstructure of electrospun nanofiber bundles. Results show that the collector pin's rotating speed not only significantly influences the arrangement of nanofibers in bundle but also the crystallinity and porosity of nanofiber bundles, which further influence the tensile strength and failure strain of nanofiber bundles. (C) 2014 Elsevier B.V. All rights reserved