Arsenite　is　the　predominant　arsenic　species　in　flooded　paddy　soil,　and　arsenite　bioaccumulation　in　rice　grains　has　been　identified　as　a　major　problem　in　many　Asian　countries.　Lowering　arsenite　level　in　rice　plants　and　grain　via　accelerating　arsenite　oxidation　is　a　potential　strategy　to　help　populations,　who　depended　on　rice　consumption,　to　reduce　the　internal　exposure　level　of　arsenic.　We　herein　isolated　a　strain,　Achromobacter　xylosoxidans　GD03,　with　the　high　arsenite-oxidizing　ability　and　plant　growth-promoting　traits.　We　observed　that　arsenite　exposure　could　promote　A.　xylosoxidans　GD03　to　excrete　indole-3-acetic　acid　and　thus　promoted　rice　growth.　The　pot　culture　experiments　of　Indica　rice　cultivar　Guang　You　Ming　118　(GYM118)　demonstrated　that　A.　xylosoxidans　GD03　inoculation　of　paddy　soil　(4.5-180　x　10(8)　CFU　GD03/kg　soil)　significantly　accelerated　arsenite　oxidation　in　flooded　soil.　The　daily　arsenic　oxidation　rate　with　GD03　inoculation　was　1.5-3.3　times　as　that　without　strain　GD03　inoculation　within　the　whole　growth　period　of　Indica　GYM118　in　the　presence　of　the　native　microflora.　It　thus　led　to　a　34-69%,　43-74%,　24-76%　and　35-57%　decrease　in　arsenite　concentration　of　the　stems,　leaves,　bran　and　grain　of　Indica　GYM118　respectively　and　a　59-96%　increase　in　rice　grain　yield.　The　paddy　soil　inoculated　with　40.0　mL/kg　of　A.　xylosoxidans　GD03　resulted　in　a　lowest　As(III)　concentrations　in　all　rice　organs　of　Indica　GYM118,　which　equivalent　to　only　24-50%　of　the　As(III)　concentrations　in　the　group　without　GD03　inoculation.　The　results　highlight　that　a　highly　arsenite-oxidizing　bacterium　could　accelerate　arsenite　oxidation　of　paddy　soil　when　facing　competition　with　the　native　microflora,　thus　decrease　arsenic　toxicity　and　bioavailable　soil　arsenic.