Rab proteins constitute the largest subfamily of the Ras superfamily of small GTPase and regulate different vesicular trafficking pathway in eukaryotic cells.The number and function of Rab family proteins display divergences in different species.In order to understand the diversity of Rab gene,9 new Rab genes,EoRab1A,EoRab2b,EoRab2c,EoRab2d,EoRab6,EoRab7,EoRab2-like,EoRabL2 and EoRan(GenBank accession no.HM371131-HM371139),were obtained from the ciliate Euplotes octocarinatus.Sequences analysis showed that the Rab gene family contains not only evolutionary conservative core function genes,but also function-specific genes in Euplotes.