In order to understand the molecular regulative mechanism of rice (Oryza sativa) Na⁺/H⁺ antiporter (OsNHX1) in plant response to abiotic stresses,a 2 000 bp upstream region of OsNHX1 gene was cloned and transformed into onion epidermal cells by particle bombardment to detect the promoter’s activity and expression pattern under various abiotic stresses.Full length OsNHX1 and Cterminal truncated OsNHX1 (OsNHX1dC) gene were also cloned and transformed into Arabidopsis thaliana separately by floral dipping method to investigate the function of OsNHX1 Cterminal.The results showed that the OsNHX1 promoter was induced by abiotic stresses and the GUS activity was enhanced significantly under salt,drought and ABA treatments.The assays of germination rate,root length,MDA and relative water content (RWC) exhibited that overexpression of OsNHX1 improved the salt and drought tolerance of transgenic plants,whereas no distinguishing difference was found between the OsNHX1dC transgenic and wildtype plants,suggesting that OsNHX1 contributed to an improved tolerance to salt stress in plants and the Cterminal tail was critical for the activity of Na⁺/H⁺ antiporter.