LiNiO2 was prepared by reaction of stoichiometric amounts of thoroughly-mixed LiOH•H2O and preoxidation nanometer-scale Ni3O2(OH)4 powders in O2 at the temperature of 700℃ for 6h. The products were tested by XRD, XPS, SEM and electrochemistry methods. It was shown that product was LiNiO2 single-phase, and the valence of nickel was+3; the average size of it was 40nm; its initial charge specific capacity is 168mAh•g-1 and the coulomb efficiency is 90%; the second charge specific capacity is 160mAh•g-1 and the coulomb efficiency is 96%.