The MoS2 nanoflakes have been successfully prepared by a novel mechanical activation method, in which the ball-milled mixture of MoO3 and S was used as reactants and then calcined at 600 degrees C for 2 h in an atmosphere of At. The ball milling played a crucial role not only in the reduction of particles size but also in the homogeneous distribution of reactants, and created micro-domains of reactors to produce nanoflakes. The length and thickness of the obtained MoS2 nanoflakes were less than 100 and 2 nm, respectively. These novel structures of thin nanoflakes had short and low stacked layers, providing more exposed rims and edges, which indicated potential applications in highly active catalysts. Furthermore, the closed structures like quasi-fullerene and nanotubes were also obtained by the rolling of nanoflakes at higher temperatures. Crown Copyright (c) 2009 Published by Elsevier B.V. All rights reserved.