Abstract: Abstract: Nitrification inhibitors such as nitrapyrin (2-chloro-6- (tricholoromethyl)-pyridine, CP) are co-applied with nitrogen fertilizers to prevent nitrification and improve the efficiencies of fertilizers in cropland, but its effectiveness depends on a number of soil characteristics. Nitrapyrin was reformulated by new technology and its purity has achieved 98%. The effectiveness improved a lot because of the greatly reduced impurities. In order to study the effects of soil pH value and soil moisture on the inhibition efficacy of new reformulated nitrapyrin, soil incubation experiments were carried under dark and aerobic conditions (25 ℃ constant temperature and 80% humidity) to discuss the implications of nitrapyrin on dynamic changes of inorganic nitrogen, nitrification intensity and nitrification inhibition rates' changing rules in different soil regime. Results indicated that ammonium concentrations decreased while nitrate concentrations and apparent nitrification rates had an ascending tendency as pH value increased. Nitrogen application combined with nitrapyrin significantly decreased the amount of disappeared ammonium and inhibited nitrification at all pH levels. At the 9th day, nitrification inhibition rate at pH value of 7.70 was highest, up to 91.53%. However, nitrification inhibition rates at low pH value decreased slower than that at high pH value. At the 45th day, nitrification inhibition rate at pH value of 4.66 was 36.43%, higher than other treatments. Nitrate concentration and apparent nitrification rate were highest in soils with 60% of the maximum water holding capacity (WHC). Nitrapyrin application inhibited nitrification at all soil moisture levels. Nitrification inhibition rate in soils of moisture levels was 40%WHC>60%WHC>80%WHC. In conclusion, nitrapyrin should be more suitable for application in acidic soil and upland soil. Results in our study are expected to provide scientific basis for the optimal soil conditions in practical application of new nitrapyrin.