Meso-scale BiFeO3 octahedral particles were synthesized by a hydrothermal method through modulating KOH concentration in the precursor solution. The morphologies of BiFeO3 particles were observed by scanning electron microscopy (SEM), displaying a morphological transformation from sphere to regular octahedron with the increase of KOH concentration. The time-dependent particle growth was also studied by SEM and the final products, octahedral BiFeO3 particles, were characterized by electron backscatter diffraction (EBSD) for understanding the crystalline growth. EBSD results show that the rhombohedral BiFeO3 octahedron is covered by eight crystal plane (001)(hex), which is different from the previous report. The possible mechanism of crystal growth is discussed. (C) 2015 Published by Elsevier B.V.