In this paper, nano-scale LiFePO4/C composite was prepared by adding monocarboxylic acid (benzoic acid), dicarboxylic acid (oxalic acid) and dicarboxylic acid (citric acid) as additives in ethylene glycol. A systematic description of the impacts from the number of carboxyl groups on the morphology and electrochemical properties of LiFePO4/C composite in the ethylene glycol system was provided. And the significantly size reduction and similar morphology to uniform rice grain were observed after the surface grafting reaction of ethylene glycol with carboxylic acids on the LiFePO4/C particle surface. Furthermore, the experiments indicated regular changes in the dispersibility and electrochemical properties. The sample in which citric acid was added performed best in terms of dispersibility with the particle size of about 800 nm, and also good regarding electrochemical property with first discharge capacity of 148.13 mAh/g and coulombic efficiency of 97.97%.