The subsolidus of Nd 2O 3 SrO TiO 2 system were determined at 1200℃. Two ternary compounds, SrO·Nd 2O 3·3TiO 2 and SrO·Nd 2O 3·4TiO 2, were confirmed in the ternary system. The latter exists over a solid solution area. Discrepancies among the various stoichiometric compounds claimed in literature in the binary system Nd 2O 3 SrO were explained. Only one compound, Sr 3Nd 4O 9, was confirmed at 1200℃. Its structure belongs to orthorhombic with a =1.221 nm, b =1.016 nm, c =0.7138 nm, Z =3 and unit cell volume 0.8852 nm 3. The electrical conductivity and dielectric constants of some phases have been measured. All phases measured are poor semiconductor. The subsolidus of Nd 2 O 3 SrO TiO 2 system were determined at 1200 ° C. Two ternary compounds, SrO · Nd 2 O 3 · 3TiO 2 and SrO · Nd 2O 3 · 4TiO 2, were confirmed in the ternary system. The latter exists over a Only one compound, Sr 3Nd 4O 9, was confirmed at 1200 ℃. Its structure belongs to orthorhombic with a = 1.221 nm, b = 1.016 nm, c = 0.7138 nm, Z = 3 and unit cell volume 0.8852 nm 3. The electrical conductivity and dielectric constants of some phases have been measured.