Laboratory work had been conducted to evaluate NO₂^- and NO₃^- accumulation capacity in the process of nitrification in 9 Chinese agricultural soils, and to investigate stability of NO₂^- in the 9 soils. Dynamic procedure was also done to observe the duration of NO₂^- in 3 soils of different properties and locations at the same NH₄⁺ levels. Results showed that acid and fine-textured soils, Red earth and Yellow-brown earth, had no NO₂^- accumulation at all NH₄⁺ levels, while alkaline or calcareous soils, such as Sajiang black soil, Fluvo-aquic soil, Coastal solonchaks, Cinnamon soil, Irrigated desert soil, and Sierozem had significant NO₃^-accumulation. NO₂^- accumulation in each soil of pH>7 increased with the elevation of NH₄⁺ levels. NO₂^- in 2 acid soils was independent of the NH₄⁺ levels, but in the other 7 soils inhibited by high NH₄⁺ input. It was found that NO₂^- was unstable in acid soils, but durable in alkaline soils or even in neutral soils. The results obtained in the study showed that NO₂^- accumulation in the process of nitrification in soils with pH more than 7 should attract more attention.