Abstract: Actinide coordination complexes are not only important species involved in nuclear fuel cycle, but also serve as model systems from which the influence of 5f electron as well as relativistic effect on the structures and reactivities of actinide complexes can be derived. Investigations on actinide coordination complexes in solution are usually complicated due to the presence of solvent molecules and counterpart anions, while all these effects could be under control when the coordination chemistry of actinide complexes is probed in the gas phase. With the help of various gas phase dissociation techniques, ion-molecule reactions as well as quantum chemical calculations, the intrinsic properties of actinide elements and their influences on the gas phase chemistry of actinide complexes are unveiled. Herein, recent progresses on multiply charged actinide complexes, actinyl oxidation and activation, actinyl-crown ether complexes, spectator-ligand-addition induced reaction and effective charge densities of actinyls are presented. The discussion is mainly focused on the formation, characterization and reaction mechanism of these actinide coordination complexes.