1-D and 2-D organic nanostructures formed by supramolecular self-assembly on HOPG(0001)from molecules containing amide and carboxylic moieties have been investigated with scanning tunneling and force microscopy operated in ambient conditions. A Precise determination of the structure of the monolayer of arachidic acid on graphite was found from moire pattern resulting from tunneling current contributions from both the monolayer and the substrate. Wedge-shaped benzamide amphiphilic molecules deposited on HOPG mainly showed 1-D structures. Systematically varied molecular geometry and head groups reveal the architecture of nanowires which are distinctly different from their columnar mesophase in solution.