Aiming at improving the electrochemical rate capability and cyclic performance of LiNi0.5Mn1.5O4，two step solid-state reaction was adopted to synthesize LiNi0.5Mn1.5O4-xFx（x=0, 0.05, 0.1, 0.15, 0.2）cathode materials.The effect of F-doped on the performance of LiNi0.5Mn1.5O4 was investigated. X-ray diffraction, scanning electron microscopy, the charging-discharging test, cyclic voltammetry tests, electrochemical impedance spectroscopy were employed to study their properties.The results showed both the doped and un-doped cathode materials were cubic spinel structure with clearly defined shape and uniform particle size distribution. For the cathode materials doped with 0.1F presents the best electrochemistry performance, at the charge-discharge rate of 0.1, 0.5, 1, 2 and 5C, its initial discharge specific capacity was 129.07, 123.59, 118.49, 114.49, 92.57mAh/g, respectively. When cycled at 1C rate, above 98.84% of its initial capacity can be retained after 30 cycles for LiNi0.5Mn1.5O3.9F0.1.