In this Letter, a tight-binding many body potential is used to simulate the melting process. A splitting second peak is first observed in the pair correlation function which implies supercooled feature. The splitting second peak is the consequence of the disordered local atomic structures. The curves of internal energy, root mean square bond length and the local clusters are used to monitor the phase transition. We show that upon heating the nanowire undergoes a coexistence of liquid and crystalline units. (C) 2004 Elsevier B.V. All rights reserved.