Microwave dielectric ceramics are used in communications devices. Such materials need high relative permittivity, high dielectric quality factor and be temperature stable. Important candidates are based on Ca(1-x)Nd2x/3TiO3. Their properties are controlled by the microstructure including domains. By Raman spectroscopy and X-ray diffraction we found evidence for a phase transition from ortho Pbnm to ortho Cmcm at 200-450oC for ceramics with x 0.39) we found a 20°C structure of P2/m with a progression to a fully ordered structure for Ca0.1Nd0.6TiO3 (x = 0.9). The objective of the experiment is to understand the mechanisms controlling microstructure and properties of ceramics in the system Ca(1-x)Nd2x/3TiO3 by determining the structure sequence and transitions.