The hexagonal-disc-shaped MgB2 single crystals were synthesized under the high-pressure conditions. The crystal symmetry, lattice constants as well as the Laue pattern of these single crystals were obtained from X-ray micro-diffraction. A crystallographic mapping showed that the edge and the c-axis of hexagonal-disc shape exactly matched the [10 (1) over bar0] and [0001] directions of the MgB2 phase. This clearly confirmed that above well-shaped single crystals could be excellent samples to study the unsolved direction dependencies of the physical properties. (C) 2003 Elsevier B.V. All rights reserved.