A series of LiMn2−x Cr x O4 (x=0, 0.01, 0.05, 0.1, 0.2) has been synthesized by a modified citrate route with combustion. The influence of the substitution of Cr for Mn on the electrochemical performances was investigated and compared. The results show that Cr substitution in spinel LiMn2O4 can effectively depress the capacity fading over 4V and improve the cycleability.