Combined application of nitrogen fertilizers with nitrification inhibitors is an effective measure to increase the nitrogen efficiency，reduce the reactive nitrogen loss and decrease the risk of environmental costs.To explore the mechanism of nitrification of different types and dosages of nitrification inhibitor in different soils，laboratory incubation experiments were used to set different dosages of three nitrification inhibitor types[dicyandiamide (DCD)，3，4-dimethylpyrazole phosphate (DMPP)and 2-chloro-6-(trichloromethyl)pyridine (NP)] to study their effects on inorganic nitrogen content，soil pH and soil apparent nitrification rate of soils(red soil，paddy soil，fluvo-aquic soil)in different regions of China.The results showed that compared with ammonium sulfate treatment，the three kinds of nitrification inhibitors could inhibit the conversion of ammonium nitrogen to nitrate nitrogen in both paddy soil and fluvo-aquic soil，and the inhibitory effect on the nitrification process in fluvo-aquic soil was better than that in paddy soil.The three kinds of nitrification inhibitors had no obvious inhibitory effect on the nitrification of red soil，and the difference in soil pH was the main reason that affected the effect of nitrification inhibitor.In addition，as the dosage of DCD and NP increased，the inhibitory effect of nitrification in paddy soil and fluvo-aquic soil became more obvious，while DMPP had no obvious dosage effect on the inhibition of nitrification in the two kinds of soils.In paddy soil，the inhibitory effect of NP was stronger than that of DMPP and DCD；in the fluvo-aquic soil，the inhibitory effect of DCD was better than that of NP and DMPP，which was caused by the differences in their inhibitory mechanism and characteristics of different nitrification inhibitors.In summary，it was particularly important to select suitable nitrification inhibitor types and dosages for specific soil types for optimizing nitrogen fertilizer management and improving nitrogen use efficiency in agriculture.