Research of the analysis of particle nano LiCoO2 phase as cathode material of lithium ion based batteries rechargeable using XRD has been done. Particle Nano LiCoO2 are synthesized using planetary milling technique followed by sonication. The morphology of particle nano LiCoO2 are characterized by using Scanning Electron Microscope (SEM) dan Transmission Electron Microscope (TEM), the phase of particle nano LiCoO2 have been analyzed using XRD. The results show that the size of the particle nano LiCoO2 isare 20-40 nm, the phase of n-particles LiCoO2 is rhombohedral, R-3m, with a = b = 2.82 Å and c = 14.08 Å, where LiCo formed octahedral symmetry, 3-3m, and CO2 to formed tetrahedral symmetry, 63m.