This paper reports that a simple chemical vapour deposition method has been adopted to fabricate large scale,high density boron nanocones with thermal evaporation of B/B2O3 powders precursors in an Ar/H2 gas mixture at the synthesis temperature of 1000-1200℃.The lengths of boron nanocones are several micrometres,and the diameters of nanocone tops are in a range of 50-100 nm.transmission electron microscopy and selected area electron diffraction indicate that the nanocones are single crystalline α-tetragonal boron.The vapour-liquid-solid mechanism is the main formation mechanism of boron nanocones.One broad photoluminescence emission peak at the central wavelength of about 650 nm is observed under the 532 nm light excitation.Boron nanocones with good photoluminescence properties are promising candidates for applications in optical emitting devices.