The optical oxygen sensors were prepared using the some Ru(II) polypyridyl complexes, tris(4,7'-diphenyl-1,10'-phenanthroline) ruthenium(II) dichloride (Ru(ph 2 phen) 3 2 + ), tris(1,10'-phenanthroline) ruthenium(II) dichloride (Ru(phen) 3 2 + ) and tris(2,2'-bipyridine) ruthenium(II) dichloride (Ru(bpy) 3 2 + ), electrostatically attached to anionic polymer, poly(acrylic acid) and poly(sodium-4-styrene sulfonate) chemisorption thin film onto alumina plate. These sensing films were good linearity using modified Stern-Volmer plot based on two-site model (oxygen-accessible site and oxygen-difficult accessible site) in total oxygen concentration region. These results show that Ru(II) polypyridyl complexes attached to anionic polymer films onto alumina plate can be developed for a highly sensitive device for oxygen sensing. Especially, the superior oxygen sensors are developed using Ru(II) polypyridyl complex in poly(sodium 4-styrene sulfonate) film.