Selenium　(Se)　in　paddy　rice　is　one　of　the　significant　sources　of　human　Se　nutrition.　However,　the　effect　of　arsenic　(As)　pollution　in　soil　on　the　translocation　of　Se　species　in　rice　plants　is　unclear.　In　this　research,　a　pot　experiment　was　designed　to　examine　the　effect　of　the　addition　of　50　mg　As/kg　soil　as　arsenite　or　arsenate　on　the　migration　of　Se　species　from　soil　to　indica　Minghui　63　and　Luyoumingzhan.　The　results　showed　that　the　antagonism　between　inorganic　As　and　Se　was　closely　related　to　the　rice　cultivar　and　Se　oxidation　state　in　soil.　Relative　to　the　standalone　selenate　treatment,　arsenite　significantly　(　p　＜　0.05)　decreased　the　accumulation　of　selenocystine,　selenomethionine　and　selenate　in　the　roots,　stems,　sheaths,　leaves,　brans　and　kemels　of　both　cultivars　by　21.4%-100.0%,　40.0%-100.0%,　41.0%-100%,　5.4%96.3%,　11.3%-100.0%　and　26.2%-39.7%　respectively,　except　for　selenocystine　in　the　kemels　of　indica　Minghui　63　and　selenomethionine　in　the　leaves　of　indica　Minghui　63　and　the　stems　of　indica　Luyoumingzhan.　Arsenate　also　decreased　(　p　＜　0.05)　the　accumulation　of　selenocystine,　selenomethionine　and　selenate　in　the　roots,　stems,　brans　and　kernels　of　both　cultivars　by　34.9%-100.0%,　30.2%-100.0%,　11.3%-100.0%　and　5.6%-39.6%　respectively,　except　for　selenate　in　the　stems　of　indica　Minghui　63.　However,　relative　to　the　standalone　selenite　treatment,　arsenite　and　arsenate　decreased　(　p　＜　0.05)　the　accumulation　of　selenocystine,　selenomethionine　and　selenite　only　in　the　roots　of　indica　Minghui　63　by　45.5%-100.0%.　Our　results　suggested　that　arsenite　and　arsenate　had　better　antagonism　toward　Se　species　in　selenate-added　soil　than　that　in　selenite-added　soil;　moreover,　arsenite　had　a　higher　inhibiting　effect　on　the　accumulation　of　Se　species　than　arsenate.　(c)　2024　The　Research　Center　for　Eco-Environmental　Sciences,　Chinese　Academy　of　Sciences.　Published　by　Elsevier　B.V.