Ammonia is a very soluble gas in water. The stage of NH3 and NH4+ is affected by pH and temperature. This study reports an ammonia removal by an air stripping tower which is filled up with packing bed (Intalox Saddles). This tower is an apparatus that removes only isolated NH3 by air stripping. In vitro removal, the study has revealed that the ammonia removal ratios are 97.3, 95.3, 95.0 and 91.5% when the flow rates of each test solution are 100, 200 and 300 ml/min. at the condition of pH 11.0. It also revealed that the ammonia removal rates were more than 90% without regard to the test solution's initial concentration at pH 11.0 at the flow rate of 100 ml/min. At pH 9.0, it revealed only 18% removal rate. Each result agrees with the theoretical values of ammonia in water. These studies suggest that our ammonia removal system is effective in artificial kidney with dialysate regeneration.