Scanning tunneling microscopy (STM) was used to study molecular adsorption behavior on reconstructed Au(111) surface. The STM images of ethyl 4-[2-(2-pyrazyl)ethenyl]cinnamate (E25PC) molecules adsorbed on Au(111) revealed ordered nucleation of molecular islands at the initial growth stage. The islands grew with spacing 38 Å in rows 77 Å apart. The periodicity of 38 Å×77 Å corresponds to that of STM images of bare Au(111) reconstructed surface in air. The behavior of molecules adsorbed on Au(111) is discussed from a view point of Au(111) herringbone reconstruction
