By　employing　non-equilibrium　Green＇s　function　method,　we　calculated　the　spin　transport　through　quantum　dot　(QD)　embedded　on　AB　ring　with　Rashba　spin-orbit　(SO)　interaction　and　magnetic　field.　The　results　show　that　the　spin　polarization　can　be　controlled　by　adjusting　either　SO　interaction　or　the　magnetic　field　applied　on　the　QD.　Furthermore,　a　new　parameter　(lambda)　is　defined　to　describe　the　effect　of　magnetic　field　on　SO　coupling　interaction.　And　it　is　found　that　the　effect　of　SO　coupling　is　suppressed　with　increasing　the　magnetic　field.　(c)　2006　Elsevier　B.V.　All　rights　reserved.