ADP-ribosylation factors (Arfs) are a family of Ras-related, low molecular mass (~20kDa), GTP-binding proteins that are expressed in all eukaryotes. They regulate intracellular vesicular trafficking along secretory and endocytic pathways and play a role in actin cytoskeleton reorganisation. The Arf family in mammals consists of six Arfs (Arfl-6), fifteen Arf-like (Aril-16), Sari and TR1M23 proteins. A few years ago, using a proteomic approach, a novel Arf protein, Arl8b, was discovered. However, Arl8b is not well studied yet. In this thesis, the biochemical and cellular characterisation of Arl8b has been discussed.