Abstract: Dunaliella salina small GTP-binding Protein Gene（GenBank Accession No.JN989548）was cloned by RT-PCR and RACE technology, named DsRab, the bioinformatics-analysis was performed, and the DsRab gene expression pattern was studied under 3 mol/L NaCl by Real-time quantitative RT-PCR method. The results showed that the full length of cDNA for DsRab Gene was 1 299 bp, which contains 78 bp 5'UTR, 609 bp 3'UTR and 612 bp ORF.The ORF codes a 203 amino acids protein with four GTP/GDP binding conserved domains, one effector domain, a cysteine residues at the COOH-terminus, and five common domain of Rab sub-family；Secondary structure prediction indicated that the α-helix, β-strands and random coil in it were 32.02% of, 23.65% and 44.33%. Protein homologue analysis showed that the DsRab shared high homology with Ypt/Rab from other species. The real-time quantitative PCR（RT-PCR）revealed that the expression of DsRab gene was increased by 4.9-fold under 3 mol/L NaCl comparising with that under normal level（including 1.5 mol/L NaCl）（P<0.01）. Key words: Dunaliella salina Small GTP-binding protein gene RACE Bioinformatics-analysis QRT-PCR