Two new tungsten bronze ferroelectrics Sr6-nPrnTinNb10-nO30 (n=1, 2) were synthesized and characterized. Sr5PrTi3Nb7O30 and Sr4Pr2Ti4Nb6O30 had tetragonal filled tungsten bronze structure at room temperature, and exhibited weak ferroelectric nature with remnant polarizations (P-r) of 0.81 and 0.8 mu C cm(-2), respectively. Sr5PrTi3Nb7O30 showed diffused relaxor behavior with the Curie temperature T-c, at around 70 degrees C (at 1 MHz), while Sr4Pr2Ti4Nb6O30 showed diffused normal ferroelectric transition with T-c at 182 degrees C. Their dense ceramics had dielectric constant of 550 and 325, and dielectric loss (tan delta) of 0.05 and 0.006 for Sr5PrTi3Nb7O30 and Sr4Pr2Ti4Nb6O30 at 1 MHz, respectively. Heterogeneous mixtures of the two compounds might be used to fabricate temperature-stable dielectrics. (C) 2010 Elsevier B.V. All rights reserved.