Dielectric ceramics were synthesized and characterized in the BaO-La2O3-TiO2-Ta2O5 quaternary system for the three typical compositions: Ba3La3Ti5Ta5O30, Ba4La2Ti4Ta6O30 and Ba5LaTi3Ta7O30, which formed the filled tungsten-bronze structures. The present ceramics indicated high dielectric constant (127.7-148.1) and low dielectric loss tand (in the order of 10-4-10-3 at 1MHz). Meanwhile, the temperature coefficient of dielectric constant varied from -728 to -1347 ppm/C with increasing Ba and Ta and decreasing La and Ti concentration in the temperature range of 20-85 C. The present ceramics are promising candidates for high-and low loss dielectric ceramics, and the suppression of should be the primary issue in the future work.