Modified electrospinning apparatus has been developed for continually fabricating nanofiber staple yarns. For this purpose, a pair of rotating metal tubes was introduced to collect the aligned electrospun nanofibers and then twist them into yarns. Between the metal tubes, a rotating plastic tube was inserted to wind the yarns. By adjusting the rotation speed of all tubes, the twist of the nanofiber staple yarns can be controlled. The mechanical behaviors of polyacrylonitrile nanofiber staple yarns have been carried out as well. The results show that the nanofiber staple yarns hold excellent mechanical behaviors, which are capable of using as functional textile fabrics. (C) 2011 Elsevier B.V. All rights reserved.