HydrotHermal SyntHeSiS, impedance and optical propertieS of tm-doped SrBi 2 nb 2 o 9 ceramicS in this study, Strontium bismuth niobate (Srbi 2-x tm x nb 2 o 9 with 0 ≤ x ≤ 0.1) doped by tm was synthesized using by the hydrothermal method. the microstructure and electrical properties were mainly investigated. XRd analysis showed a single-phase orthorhombic structure for tm-doped SrBi 2 nb 2 o 9 samples. the crystallite size is anisotropic and the strain is apparently independent of tm amount. dielectric properties for doped SrBi 2 nb 2 o 9 with tm 3+ ion have the same trend discussed for the pure sample. ftir resulats showed that nbo 6 octahedral is formed, on one hand, and on the other hand, it shows that spectras for doped and undoped samples are nearly the same. the Cross-section of ceramics showed the plate-like morphology, also the distribution of the pore in ceramics are observed for all samples. tm dopants produce only minor changes in the impendence parameter values at room temperature. the luminescent (PL) properties of tm-doped SrBi 2 nb 2 o 9 ceramic powders were investigated. the optimum tm 3+ concentration for the maximum PL intensity was found to be at x = 0.075.