Uniform minor Mn-doped LiFePO4/C cathode materials are synthesized and their electrochemical performances are investigated systematically. Via tuning the doping amount of Mn, it is found that the well crystallized LiFePO4/C doped with 11000ppm Mn gives the highest discharge capacity of 165mAhg−1 at 0.1C at room temperature. Remarkably, it holds a quite stable cycling performance at 45°C, with capacity retention of 97.4% after 200 cycles using a high rate of 3.0C, and its low-temperature (−20°C) specific capacity maintains at high up to 131.4mAhg−1 at 0.1C, higher than that of the majority reports. The higher or lower Mn-doping amount than 11000ppm is found to have less positive impact on the performance of LiFePO4/C. Such phenomenon may be attributed to the negative cooperative effect of Mn doping, which enlarges the crystal space for improving the Li+ transfer under low dose due to the large radius of Mn, but increases the charge transfer resistance and declines the performance under high dose owing to its poor intrinsic kinetics.