How to increase fertilizer use efficiency (FUE) has been an urgent problem still unsolved for agriculture development and environment protection. In this paper, the common approaches to improve FUE were briefly reviewed, and the main reasons for the lower FUE in China were discussed. The loss of nutrients from the cropland is the basic course lead to low FUE, while adsorption or fixation of nutrients in soil is not the main reason for the low FUE. From the aspect of nutrients uptake, the large portion of nutrients distributed in the bulk soil could not be assimilated efficiently by crop roots explains the fundament of the low FUE. Based on the limited movement and diffusion of the nutrients in soil, the limited soil volume from which crop root could absorb nutrients efficiently, and the concentration of the nutrients determined nutrients uptake efficiency by roots, the root-zone fertilization technique was proposed as the key and indispensable approach for the high NUE in future. The definition of root-zone fertilization technique, where this technique is suitable, and what scientific fundaments need to be revealed in future were also discussed in this paper.