Monolayer and bilayer of 17,19-dotetracontadiyne (DTDY) on a graphite substrate were studied by scanning tunneling microscopy at a liquid/solid interface of phenyloctane solution. The orientation of the layers was examined with respect to the highly oriented pyrolitic graphite. The first layer grew very quickly with many small domains some tens of nm in diameter, and the alkyl chains of the molecule in each domain align epitaxially along the a(g)-axis of graphite. When the solution remains at room temperature, the second layer of DTDY grew epitaxially on the first layer and the domain size was much larger than that of the first layer. (C) 2002 Elsevier Science B.V. All rights reserved.