The porous Li1.2Ni0.13Co0.13Mn0.54O2 nanoplate is prepared by colloidal crystal template assembled by the poly (methyl methacrylate) (PMMA) beads. Scanning electron microscopy and transmission electron microscopy results show that the nanoplates of porous solid solution cathodes are composed of nanoparticles with a size range of 30 nm, which interweave together forming an open porous structure. Electrochemical tests show that porous Li1.2Ni0.13Co0.13Mn0.54O2 cathode could deliver higher discharge capacity than that of bulk Li1.2Ni0.13Co0.13Mn0.54O2 cathode at all C-rates. The enhanced structural stability reflected by high ratios of integrated Intensity I(003)/I(104) and lattice parameters c/a, high specific surface area, a fast reaction and ionic diffusion kinetics of the nanoplates are considered attributable to the improved electrochemical properties.