pH of leachate plays an important role in translocation of matters in the soil and form of substances in soil solution in subtropical acid soils. To study relation between H⁺ released in nitrification and pH of soil leachate in the soils, an indoor simulated leaching experiment was carried out for 112 days using soil samples different in nitrification intensity amended with 0, 150, and 300 mg kg^-1 (NH₄HCO₃)-N, separately and leached 17 times, once a week Results show that the leachates from the acid soils were not necessarily acid, and their pH values depended on combined effect of H⁺ release rate from nitrification and acid buffering capacity of the soils. When nitrification brought the concentration of NO₃^- in the leachate up to a certain level, pH value of the leachate dropped abruptly. The critical point NO₃^-concentration showed a linear positive relationship (p<0.05) with the soil base saturation and the application rate of (NH₄HCO₃)-N. Therefore, leachates from the upland soil highest in nitrification intensity with base saturation 81% remained neutral, while leachates from the soil under shrubbery, moderate in nitrification intensity and 21% in base saturation dropped below 4.0 in pH value.