[ $LiNiO_2$ ] was synthesized by the solid-state method after mixing $LiOH{cdot}H_2O$ and $Ni(OH)_2$ with SPEX mill. The optimum condition for the synthesis of $LiNiO_2$ was the calcination at $750^{circ}C$ for 30h in $O_2$ stream after milling for 1 h. The $LiNiO_2$ synthesized under this condition showed relatively large value of $I_{003}/I_{104}$ and relatively small value of R-factor. When $LiNiO_2$ was cycled in 2.7$~$4.15 V at 0.1C-rate, the first discharge capacity was not very large (145.8 mAh/g) but it showed good cycling performance. When $LiNiO_2$ was cycled in 2.7$~$4.2 V at 0.1C-rate, the first discharge capacity was large but ,it showed poor cycling performance probably because of the transition of H2 hexagonal structure to H3 hexagonal structure. In addition, when $LiNiO_2$ was cycled in 1.0$~$4.8 V at 1/24C- rate, the first discharge capacity was very large (257.7 mAh/g) and the discharge capacity increased with the number of cycles.