Layered LixCoO2 (x=1.0, 1.05, and 1.1) samples prepared by eutectic self-mixing technique were characterized by solid-state Li-7 MAS NMR. Simulations of Li-7 NMR spectra were performed to identify the lithium sites. For Li1.0CoO2, a unique lithium site was observed at about 0 ppm, which was assigned as octahedral site having C-Q=0.92 MHz and eta=0. By increasing content of lithium in LixCoO2, additional lithium sites having larger quadrupolar interaction were observed. For Li1.05CoO2, an additional site including octahedral site was observed and determined as C-Q=3.0 MHz and eta=0. A resonance at about -15 ppm was also detected. For Li1.1CoO2, a lithium site having C-Q=3.77 MHz and eta=0.1 was additionally observed. The electrochemical property of LixCoO2 was extremely related with local environment of lithium sites. (C) 2004 Elsevier B.V. All rights reserved.