The full-length cDNA of the vacuolar pyrophosphatase(VP1) from halophyte Chenopodium glaucum was cloned by using RACE technique,and was named as CgVP1.It contained a 2 292 bp open reading frame (ORF) encoding 763 amino acid polypeptide.This sequence of CgVP1 contained DVGADLVGKVE,a consensuses sequence in plant VP1 proteins.CgVP1 shared more than 86% similarity with VP1s from other plants.Transmembrane domain prediction showed that CgVP1 contained 12 trans-membrane helix regions,and sub-cellularly localized in cellular membrane system.RT-PCR results showed that when C.glaucum was treated with 200 mmol/L NaCl during the germination and growth,and then treated with 800 mmol/L NaCl for 24 h,the expression of CgVP1 gene was significantly increased compared to the control which was not pre-treated with 200 mmol/L NaCl.When C.glaucum was treated with different concentrations of KCl,CaCl₂ and MgCl₂ for 24 h,respectively,the expression of CgVP1 was down regulated with the increase of the concentrations of KCl and MgCl₂,whereas CaCl₂ did not influence the expression of CgVP1.These results indicated that the expressions of CgVP1 response differentially to different types of salt treatments,and NaCl stress can induce its expression.This study can help to understand the regulatory function of VP1 in halophyte C.glaucum under salt stress.