Nano-sized TiO2 with an anatase phase is prepared by hydrolysis of titanium tetraisopropoxide in pure water. Samples are characterized by transmission electron microscopy (TEM), X-ray diffractometry (XRD) and X-ray photoelectron spectroscopy (XPS). TiO2 nanoparticles experienced two processes of phase transition, i.e., amorphous to anatase and anatase to rutile, over the temperature range from 60 to 800°C. The electrochemical properties of Li+ ion insertion in nano-sized TiO2 (anatase) electrodes is studied by voltammetry. The diffusion-limited insertion and extraction of Li ions in the anatase lattice within a region near the peak potential are dominating. The anatase TiO2 nanoparticles exhibit a large initial electrochemical lithium insertion capacity of 195mAhg−1, good reversibility, and cyclic stability.