Abstract: Ultra thin film of perfluoroctanoxylpropyl dimethyl silane with low surface free energy was fabricated on microscope glass slide substrate by means of molecular self assembly process. The contact angles of water and hexadecane on the resulting ultra thin film were measured so as to investigate the hydrophobic hydrophilic properties of the film. The chemical states of some typical elements in the ultra thin film were determined with an X ray photoelectron spectrometer. The tribological behavior of the ultra thin film sliding against AISI 52100 steel was examined with a DF PM static dynamic friction coefficient procession measurement apparatus. As the results, the self assembled monolayer showed good repellency to water and oil. It helped to decrease the friction coefficient of the substrate significantly and showed extended antiwear life at a relatively low load.