Electronic structural changes in LiTi2O4 spinel compounds upon electrochemical lithium insertions were investigated by X-ray absorption spectroscopy (XAS) measurements and first principles calculations based on spin-polarized density functional theory. Ti K-edge, O K-edge XAS spectra and theoretical calculations indicate that oxide ions as well as titanium ions are involved in electronic structural changes caused by electrochemical lithium ion insertions. The considerable effect of the oxide ions in the early 3d transition metal (titanium) oxide system is discussed in this article.