The effects of strontium substitution on the electrical properties of La 3 Ta 0.5 Ga 5.5 O 14 (LTG) are reported. Strontium substituted LTG (Sr-LTG) with a nominal chemical composition La 2.9 Sr 0.1 Ta 0.55 Ga 5.45 O 14 crystals were grown using the conventional Czochralski method under high and low oxygen partial pressures. The electrical properties and thermal behaviors of the Sr-LTG crystals were also compared with those of pure crystals. Sr substitution was found to affect the electroacoustic constants and thermal expansion coefficient clearly. These characteristics are discussed from crystallographic perspectives. The Sr-LTG crystals grown at low oxygen partial pressures exhibited higher electrical resistivity µ for pressure sensors used at high temperatures.