Abstract: A series of tetrazole derivatives were synthesized. The effect of the synthetic compounds as additives in liquid paraffin and a commercial lithium grease on the load carrying capacities and anti wear properties was examined using a four ball machine. The chemical states of the elements including N and Fe on the worn steel ball surface were examined by means of X ray photoelectron spectroscopy. As the results, the tetrazole derivatives as additives in liquid paraffin and/or commercial lithium grease help to increase the load carrying capacities and anti wear ability. N and Fe exist on the worn steel ball surface in forms of organic N containing complex and Fe3O4, respectively. It is the boundary film composed of organic N containing complex, Fe 3O 4, and other compounds acts to improve the extreme pressure and antiwear bproperties of the lubricating oil and grease.