The LiFePO4 nanoparticles with high crystallinity were prepared using polyol process without any further heating as a post step, which will greatly economize in time and energy comparing with other conventional synthesis method. The temperature of the polyol solution was rapidly increased up to 550 K and maintained for 24 h in a round-bottomed flask attached to refluxing condenser to obtain nanoparticles. The X-ray diffraction (XRD) pattern was indexed on the basis of orthorhombic olivine-type structure without any unwanted second phase. The scanning electron microscopy (SEM) images of the samples showed the needled and flaky shapes of particles with uniform size in the range of 50-250 nm. It is noted that the nanoparticle was in favor of shortening the diffusion path to improve electrochemical performance. A reversible specific capacity around 160 mAh·g-1 at 0.1C rate was achieved without capacity fading during the 20 cycles.