Quite a lot of researches on mixing vessels have been studied in chemical engineering area. Because there are a lot of papers and patents, it is difficult to understand mixing operations for engineers to design and operate mixing vessels. In this paper, the authors explain the performances of mixing vessel by the power consumption as the key word. It is shown that we can estimate the flow characteristic, the mixing characteristic, the heat transfer characteristic, and mass transfer characteristics in the turbulent mixing vessel by using the power consumption. Moreover, the power correlations presented by Hiraoka and Kamei were as useful as Nagata's correlations.