One of the most popular materials in modern science is ceramic material based on zirconium dioxide. This material is attracted attention due to its unique physical properties: high fracture toughness and bulk modulus, low thermal conductivity, extremely refractory, chemically inert, corrosion resistant, high dielectric constant. The preparation of ceramic from zirconium nanopowders is delivered possibility to obtain promising properties for the application in catalysis, the technologies of ceramics production for functional, structural and medical application, optics, etc. [1-3]. The present work is devoted to investigation of influence of Ce concentration to phase composition, crystal structure and microstructure of ceramic samples of zirconium dioxide Zr1-xCexO2 (x=0 – 0.17) annealed at 15000C. The phase composition as well as type of crystal structure of zirconium ceramic was analyzed by conventional X-ray diffractometer DRON-3M in Cu-Kα radiation and by the High resolution Fourier diffractometer (HRFD) at the IBR-2 pulsed reactor in Dubna [4]. The information about microstructure was reformed by electron microscope Zeiss Supra 55 with an EDAX Genesis detector. According to X-ray and neutron (Fig.1) data the crystal structure of investigated samples Zr1-xCexO2 (x= 0 – 0.17) are depending on the Zr/Ce concentrations. The increase of concentration of Ce ions leads to changing of crystal structure from monoclinic (P21/c) to tetragonal (P42/nmc) and volume of unit cell decreases to 69.2 Å3 (x=0.13) and to 69.7 Å3 (x=0.17).