H 2 S generation suppression by the addition of NO 3 from reagent (NR) or compost (NC), and O 2 supply (OX) was quantitatively estimated in column percolation experiments. The cumulative amounts of oxygen added exceeded 300 mmol-O/L in NR and NC, and approximately 2 mmol-O/L in OX on day 75. The cumulative amounts of H 2 S generated on day 60 in control, NR, NC, and OX were 69, 26, 71, and 31 mmol-H 2 S/L, respectively. The amounts in NR and OX were half of that in control, whereas the amount in NC was almost the same as that in control. The H 2 S generation rates from day 50 to day 60 in control, NR, NC, and OX were 0.86, 0.019, 0.75, and 0.041 mmol-H 2 S/(L·d), respectively, and the rates in NR, NC, and OX were 0.02, 0.9, and 0.05 times that in control. In this way, the H 2 S generation suppression effects of NO 3 reagent addition were observed. In NR, although NO 3 was injected from the top of the column, the suppression effect reached the deep layer.