We successfully fabricated single crystalline tetragonal boron nanobelts by a laser ablation method in a furnace without using a catalyst or hazardous boron vapor source. The boron nanobelts obtained are rectangular in cross-sectional shape with a width-to-thickness ratio of about 5, several tens of nanometers to about 150 nm in width, and several micrometers to the order of millimeters in length. The interior is well crystallized in tetragonal structure and an amorphous structure 2-4 nm thick can be seen along the surface of the nanobelt. Only boron EELS peak was detected from single nanobelts. (C) 2002 Elsevier Science B.V. All rights reserved.