Structural and functional characteristics of ceramic components highly depend on their microstructure and mechanical properties. In the production of such ceramics sintering plays extremely important role. Recently, we are working on the development and fabrication of temperature sensors for the petroleum wells. In this connection, we have developed a new alumina based ordered complex cubic peroviskite oxide ceramic Ba2AlWO5.5. During our study, we found that Ba2AlWO5.5ceramics compacts could not be densified by normal sintering route. To overcome this hurdle, we have utilized the liquid phase sintering process, using CuO additives. By addition of 1 to 2 wt% CuO, we succeeded to sinter this ceramic in the temperature range 1200 to 14000 C. Sintered Ba2AlWO5.5 ceramics were examined by X-diffraction and scanning electron microscopy to verify the presence of any extra phase due to CuO addition in the Ba2AlWO5.5 matrix. Our studies revealed that CuO addition did not affect the structural characteristics, but considerably modified the densification process, microstrutural characteristics and consequently mechanical properties of the Ba2AlWO5.5 ceramics.