Objective To explore the reasons why the contents of ammonium ion and nitrate ion in the explosion residue of emulsion explosive were lower than that of normal explosives. Methods The emulsion explosive residue samples were collected from a crime scene and an explosion experiment scene, respectively. The samples were analyzed by ion chromatography and the contents of ammonium ion and nitrate ion were quantitatively determined. Results The contents of ammonium ion and nitrate ion in blank samples, case samples and experimental samples were in the same level. Conclusions According to the emulsion explosive formula, the content of ammonium nitrate in emulsion explosive normally is in the range of 78%~82% (typical content is 74.3%). However, as advanced production technology and effective emulsifier have been employed in production process, the mixture of ammonium nitrate and composite oil in emulsion explosive is more homogeneous, and then the oxidation-reduction reactions of emulsion explosives in explosion become more thoroughly. This Results in the quite lower contents of ammonium ion and nitrate ion in the explosion residue of emulsion explosive, which is consistent with the Results of the case and the verification experiment described in this article.