The agronomic, environmental, and ecological significances of applying nitrification inhibitor (NI) have been demonstrated by many researches, but the efficiency of NI application was affected by many factors. In this paper, the effects of NI on soil N transformation, nitrate leaching and greenhouse gases emission, fertilizer N use efficiency, yield and quality of agricultural products, and availability of soil nutrients besides N were reviewed, and the factors affecting the efficiency of NI application as well as the evaluation criteria of NI were summarized.