Abstract: Gravimetric method was applied to the determination of phosphorus in LiFePO4/C.Pretreatment methods of carbon removal by ashing and filtration were compared in determination of phosphorus in LiFePO4/C using quinoline phosphomolybdate gravimetric method.The optimized conditions found were as follows:① pretreatment method of carbon removal of sample:filtration;② amount of precipitant:20 mL;③ heating temperature:90 ℃.The proposed method was applied to the analysis of samples of LiFePO4/C,giving values of recovery and RSD′s (n=9) in the ranges of 98.9%-99.8% and 0.30%-0.43%,respectively.