In this paper, cyclability of perovskite-type electrode material, Li x La1/3NbO3 for lithium ion battery has been investigated. In the case of operation voltage at 3.0–1.25V, good cyclability was observed and ascribed to the small cell volume change during the lithium insertion/removal process. In situ Nb K-edge X-ray absorption spectra suggested that no significant change in volume were caused by internal structural relaxation of NbO6 octahedron tilting. On the other hand, the capacity gradually decreased with lithium insertion/removal cycle under the operation voltage of 3.0–0.8V. From the structural study using X-ray diffraction and Nb K-edge extended X-ray absorption fine structure techniques, excess lithium insertion into perovskite structure lead to local distortion around NbO bond, and the cell volume increased slightly. These results imply internal relaxation of NbO6 octahedra play a crucial role in cyclability.