Abstract: The content of manganese in LiMn2O4 is measured with the analytical method in the industry standard，Lithium Manganate（YS/T 677—2008） at present.The sample is dissolved with phosphoric acid and nitric acid in this method，but it′s not easy to observe the phenomenon，also it sets high requirements for operators to use perchloric acid which is high corrosive and strong stimulating as oxidant.This paper adopts the method which uses ammonium nitrate as oxidant and hydrochloric acid to dissolve the sample，thus the phenomenon is obvious and the operation is safer because ammonium nitrate is stable at room temperature.By contrast with experiments，the test results of the two methods are the same，so it′s completely feasible to use ammonium nitrate oxidation method to replace perchloric acid oxidation method to measure the content of manganese in LiMn2O4 .

Key words: LiMn2O4 , perchloric acid, ammonium nitrate, volumetric method