Abstract: This paper studies the effects of Niuher navel oranges yield and Se content in Gannan Niuer seleniumrich navel oranges.The results show that applying sodium selenite to Niuer navel oranges could raise the Se content in navel oranges and yield, which increased with the enhancing sodium selenite. The selenium content amplitude determined of the Selenium-rich navel oranges were from 105 % to 2718 % compared with the comparison group. The selenium content obtained from the Selenium-rich navel oranges was from 0.009 mg / kg to 0.03 mg / kg. These results prove that the selenium enrichment effect under the condition of selenium cultivation and transformation in Gannan Niuer navel oranges is prominent.