Diamond nanocrystals with cubic and hexagonal structures have been prepared by pulsed laser induced liquid-solid (acetone1-graphite) interfacial reaction (PLIIR) at normal temperature and pressure. The structure and morphology of the resulted diamond nanocrystals were characterized by transmission electron microscopy (TEM). The Raman spectroscopy analysis of the obtained diamond nanocrystals showed that three diamond Raman lines, i.e., 1307, 1100, and 623 cm(-1) were observed. Interestingly, the Raman line at 1100 cm(-1) was identified to be original from nano-diamond. In addition, a new Raman line at 926 cm(-1) due to diamond was observed in the Raman spectra (RS). (C) 2002 Elsevier Science B.V. All rights reserved.