Lithium manganese oxides LiMn2O4 and rare earth elements doped LiNd0.01Mn1.99O4 were synthesized by microwave method. The structure and the electrochemical performances of the samples were characterized. XRD data shows both samples exhibit the same pure spinel phase. But due to the introduction of Nd3+ ion into the unit cell, the lattice parameter of the Nd-doped spinel was larger than that of the undoped one. The two samples had a similar morphology including small particle size and homogeneous particle distribution as tested by SEM. The cyclic voltammmetry and constant-current charge-discharge tested that Nd-doped spinel displayed a better reversibility and cycleability.