Mixing vessels with draft tubes are used in industrial processes, but power number data have not been published for this type of vessel. In this study, the power characteristics of a mixing vessel with draft tube were measured for various conditions of draft tube and mixing impeller geometry. The power number was found not to be affected by the geometry of the draft tube, but greatly affected by the impeller geometry. The power number of the mixing vessel with a draft tube was larger than that without a draft tube. It was also found that the power number of a vessel with draft tube and a paddle impeller or pitched paddle impeller corresponded to those of a vessel without draft tube and with a ratio of baffle width to vessel diameter of B-W/D=0.05 and 0.08, respectively.