Abstract: Rabs play important role in vesicular transport in all eukaryotic cells. The current study successfully cloned the full-length cDNA of a Rab gene of Macrobrachium rosenbergii (named MrRab11) by the rapid amplification of cDNA ends (RACE) techniques. The full-length of MrRab11 cDNA was 1381 bp, including a 226 bp 5'-terminal untranslated region (UTR), a 511 bp 3'UTR and a 645 bp open reading frame (ORF) encoding a polypeptide of 214 amino acids residues that contain a Rab domain. The calculated molecular mass of deduced MrRab11 polypeptide was 23.75 kD and the isoelectric point was 5.34. BLASTX analysis revealed that MrRab11 had significant homology to Anopheles gambiae, Daphnia pulex and Homalodisca vitripennis with the identity of 82%, 83% and 82%, respectively. Quantitative real-time reverse transcription PCR analysis demonstrated a broad expression of MrRab11 in many tissues with the highest level in hepatopancreas and then muscle and intestine. The expression level of MrRab11 in hepatopancreas was significantly (P0.05) induced by Enterobacter cloacae at 12h. These results suggest that MrRab11 may play a role in the innate immunity of M. rosenbergii.