n this work, we study the phase transition and structure properties of hexagonal Ba1-xSrxTi0.8Ga0.2O3 (x = 0.01, 0.03, 0.05, 0.07, and 0.09) systems, and also investigate the microwave dielectric property of this system. The all samples are prepared by the mixed oxide method, the structure of samples are transferred from hexagonal phase to mixed phases then tetragonal phase through the Sr-doping process, which is consistent with the thermodynamic prediction on literature. The samples are included the tetragonal phase, whose dielectric property is poorer than the hexagonal phase samples, so it also points out that the hexagonal BaTiO3 material has very good dielectric property and a large potential for application.
