In the previous report (AIChE J., 50, 871-878, 2004), a new type of the injection method of liquid CO₂ by a static mixer was proposed by the present authors for the direct ocean disposal of CO₂ at the intermediate depths (500-1500 m). The static mixer is effective for producing liquid CO₂ drops with uniform size distribution, and would have advantages of the drop size control over simple nozzle injection methods. In this study, the mixing behavior of liquid CO₂ and water and its effects on the CO₂ drop formations in the Kenics type static mixer was observed in a laboratory-scale experimental apparatus simulating the intermediate ocean conditions. It was found that the size reduction and uniformalization of the liquid CO₂ drops were mainly conducted at the first 2 element at the upstream side of the mixer. After that, the size and its deviation decreased quite gradually without coalescence of the drops.