The objective of this study was to determine the effect of injection application of pig slurry on ammonia (NH3) and nitrous oxide (N2O) emission from timothy (Phleum pretense L.) sward. The three treatments were applied: 1) only water as a control, 2) pig slurry application by broadcasting, 3) pig slurry application by injection. The pig slurry was applied at a rate of 200 kg N ha-1. Total NH3 and N2O emission, expressed as a cumulative amount throughout the measurement time (40 days), was 2.68 kg NH3-N ha-1 and 6.58 g N2O-N ha-1, respectively, in the control. The injection application of pig slurry decreased total NH3 and N2O emission by 39.8% and 33.3%, respectively, compared to broadcasting application of pig slurry. The present study clearly showed that injection application exhibited positive roles in reducing N losses through NH3 and N2O emission.