We report the fabrication in air of nucleation sites for nanometer size selective deposition with a scanning tunneling microscope (STM) for the first time. Nanometer structures between 0.8 and 50 nm for preferential nucleation sites could be produced on a graphite substrate with STM in air. We observed the migration of Au atoms deposited on the graphite with such artificial nanometer structures. It could be observed that the Au clusters reached around there stopped moving and were trapped at these sites. This finding proves the possibility of fabricating artificial nucleation sites in air by STM.