Compartmentalization of Na+ into vacuoles is an important way for cells to avoid the toxic effects of salt.Here, Arabidopsis AtCCX1 was studied in Pitch pastoris GS115.Yeast expressing AtCCX1 grew better in high H+ concentration medium and high salt medium than original strains and increased Na+ accumulation while decreasing K+ accumulation.AtCCX1 was located in tonoplast in yeast.Transport assays were indicated by fluorescence SBF I and PBF Ⅰ respectively.Results showed that AtCCX1 simultaneously took part in transport of both of Na+ and K+ and the process was inhibited by H+-ATPase inhibitor vanadate, suggesting that AtCCX1 is an H+-dependent Na+/K+ exchanger.