In this study a packed tower was selected for the treatment apparatus of NH3 gas produced in industry. Formerly, latticework packing has been used in preventive facility of treatment of NH3 gas. However, recently metallic Ralu-Pack 250YC, structured packing, is usually being used in petrochemical production plant. This study is for the application the packing to the NH3 gas treatment in wet scrubbing process. In Air/water system, hydraulic pressure drop dependent of specific liquid load and gas capacity factor was continuous and parallel from graph. The tower height can be determined by the number of transfer unit and the height of transfer unit influenced on liquid distribution.