Arrays of graphite nanocones were fabricated by oxygen-plasma etching of highly oriented pyrolytic graphite (HOPG). As it turned out gold nanoparticles, which were deposited by immersing HOPG samples pretreated with 3-(2-aminoethylamino) propyltrimethoxysilane into colloidal gold solutions, were very efficient for the self-aligned formation of graphite nanocones; the density of nanocones were found comparable with that of gold nanoparticles deposited on HOPG surfaces. We were able to control the shapes and sizes of nanocones by manipulating the plasma-etching parameters such as plasma power and etching time. In particular, nanopillars were formed using high plasma-etching power together with relatively short etching time. Graphite nanocones showed a potential to be good electron-emitters. The emission from the graphite nanocone arrays was turned on at 2.3 V/mum, and the emission current from the area of 6 mm diameter reached the level of 100 muA. (C) 2004 American Vacuum Society.