Nanocrystallized steel surface by micro-shot peening (MSP) were applied to carbon nanotube growth in this study. Micro-shot peening treatment severely deformed steel surface and nanocrystallized surface layer was formed by the plastic deformation. The grain sizes of the nanocrystallized layer were 1030 nm after 300 s of MSP treatment. On the nanocrystallized surface, carbon nanotubes were formed with thermal chemical vapour deposition without catalysts. Before carbon nanotube growth, the nanocrystallized steel surface was reduced with H(2)/N(2) gas at 600 degrees C. The carbon nanotube growth was performed at 600 degrees C with C(2)H(2) gas carried by H(2)/N(2) gas. The carbon nanotubes formed on the nanostructured surface was multi-walled carbon nanotube and the diameter was 10-20 nm. The reduction process before carbon nanotube growth was essential to form carbon nanotubes on the nanocrystallized surface with MSP. (C) 2010 Elsevier Ltd. All rights reserved.