The influence of scrubbing liquid type on the ammonia removal efficiency of wet scrubber installed in pig fattening houses was evaluated. Ammonia concentrations, which were ranged from 18.0±2.9 to 21.8±3.4 ppmv at the inlet of the wet scrubber, were reduced to 17.3±2.7, 15.5±1.9, 13.0±1.5 ppmv, respectively as a result of treatment with scrubbing liquid with water, base agent, microbial agent. It is generally known that wet scrubbers have an ammonia removal of 45~ 72%, but they have a low removal rate of 18~ 25% in this study. It was confirmed that there is a significant difference in the daily ammonia removal efficiency. The ammonia removal efficiency was 1.8~ 26 times higher at nighttime than daytime, which is seen as a result of changes in ambient temperature. The ambient temperature was about 2 C higher than that of scrubbing liquid during the day. The ammonia removal efficiency was decreased due to the ammonia volatilization as the ambient temperature increased. In maintaining the wet scrubber treatment efficiency properly, it is essential to select the scrubbing liquid type correctly and develop appropriate operation methods according to ambient temperature changes, so further research related to this needs to be conducted in the future.