We report the fabrication of dispersive one-dimensional gold nanocrystals which is an essential technology for the X-ray single-molecule technique. Gold narrocrystals approximately 16 nm in diameter, fabricated by vacuum evaporation (deposited gold thickness: 2.0 nm; substrate temperature: 375degreesC)_ on cleaved NaCl (100) substrates, were stably dispersed in aqueous solutions by dissolving the substrate. We confirmed from their X-ray diffraction patterns that the fabricated gold nanocrystals have a single orientation (200). We succeeded in monitoring diffracted X-ray spots (Laue spots) from individual gold nanocrystals with a diameter of approximately 16 nm at an exposure time of < 10 ms. (C) 2004 Elsevier B.V. All rights reserved.