In the present work, we studied the influence of substituting Pr for Bi on the structural and dielectric properties of SrBi 2-x Pr x Nb 2 O 9 (x = 0, 0.2) ceramics at room temperature. The samples were prepared by the solid-state reaction method. The XRD patterns of the doped sample corresponded well with those of the undoped samples. SEM revealed that the Pr doping brings significant change to the microstructure. The results obtained from different experimental dielectrics at room temperature are correlated to discuss the structure-property relationship with consideration of the internal microstructure, the strengths of chemical bonds (Pr-O and Bi-O) and the oxidation of Pr 3+ to Pr 4+. The dielectric constant increased with Pr-doping, while the dielectric loss decreased. Praseodymium is introduced into SrBi 2 Nb 2 O 9 to reduce the number of oxygen ion vacancies available for the conduction process.