By depositing Mg vapor generated via carbothermal reduction on boron powder in the presence of different additives, dumbbell-like MgO nanofibers, NaCl particle-decorated MgO nanofibers and camphor tree stalk-like MgO fibers were produced. SEM, TEM and EDS analysis showed that the additives of Si and NaCl deposited in the sites of stacking faults in fiber, which resulted in the growth of different morphologies of decorated fibers. (C) 2003 Elsevier Science Ltd. All rights reserved.