A formation mechanism for the growth of high-aspect-ratio TiN nanosheets on Si (1 0 0) substrate is proposed based on the anisotropic growth. Calculations of the lattice and domain misfit show that the most likely TiN crystalline plane to grow on Si (1 0 0) is TiN (4 2 2). Two growth directions of the TiN (4 2 2) plane exhibit different growth rates. The uneven growth rate results in mutually perpendicular nanosheets standing on the Si (1 0 0), which is consistent with the FESEM image of the TiN nanosheets. Also, the lattice structure of the TiN nanosheet resulting from the proposed mechanism is nearly identical to the HRTEM image of the TiN nanosheet. (C) 2008 Elsevier B.V. All rights reserved.