Nitrogen　doped　SrTiO3　powders　were　prepared　by　mechanochemical　reaction　of　SrTiO3　and　20　wt.%　of　three　kinds　of　doping　sources,　hexamethylenetetramine,　urea　and　ammonium　carbonate　using　a　high　energy　planetary　ball　mill.　The　effects　of　several　factors　such　as　the　kinds　of　nitrogen　doping　source,　milling　time,　content　of　nitrogen　source　in　the　raw　material,　post-grinding　heat　treatment　temperature　and　post-grinding　beat　treatment　atmosphere　on　the　photocatalysis　of　the　samples　have　been　studied.　The　nitrogen　doped　SrTiO3　had　yellow　color　and　possessed　two　absorption　edges　around　390　and　470　nm.　The　sample　prepared　by　grinding　the　mixture　of　20　wt.%　hexamethylenetetramine-80　wt.%　SrTiO3　followed　by　heat　treatment　at　400　degreesC　in　air　showed　the　best　performance　in　the　elimination　of　NO.　The　value　of　NO　destruction　under　visible　light　(lambda　＞　400　nm)　irradiation　attained　to　47.8%,　which　was　about　3.5　and　1.4　times　higher　than　that　of　pure　SrTiO3　and　commercial　titania　(Degussa　P-25).　(C)　2004　Elsevier　B.V.　All　rights　reserved.