Abstract: The earthing resistance of single grounding conductor or grounding grid often can not satisfy the engineering request in some projects, and for these cases the using of earthresistancereducing agent in construction process is necessary. The working principle, the applicable range, the advantages and disadvantages of earthresistancereducing agent were analyzed, and its calculating and using methods were given. It is expected that the discussion in this paper is helpful for the application of earthresistancereducing agent.

Key words: earth-resistance-reducing agent, working principle, calculating and using method