Abstract:Two red soils derived from the quaternary red clay and the tertiary red sandstone, respectively, were used to investigate effects of moisture and temperature on nitrification and denitrification activities of the soils. Nitrifiers, denitrifiers, nitrification intensity, denitrification potential and denitrifying enzyme activity were determined of the fresh soil samples having been kept placed at 4℃ (O), moistened to 40% in water holding capacity at room temperature (24℃~27℃) (M) and flooded (F) at room temperature (24℃~27℃), separately for 110 days. The results indicate that low temperature helped keep the number of nitrifiers and denitrifiers, but significantly inhibited nitrification and denitrification activities of the bacteria. Moistening contributed to maintenance of nitrification activity of the nitrifiers. Flooding, though, favored denitrification activity of the denitrifiers, it made againstsurvival of both the nitrifiers and denitrifiers. Therefore, the appropriate way to store soil samples depends on what they will be used for.