In this work we report on the ultrasonic and dielectric properties of composites consisting of conventional piezoelectric polymer, polyvinylidene fluoride/trifluoroethylene (PVDF-TrFE) copolymer of composition 70/30 mol. %, and (Pb0.75Ba0.24Sr0.01)(Zr0.53Ti0.47)O3 (BPZT) particles. BPZT fillers concentration was varied from 10 to 50 vol.%. Investigation of ultrasonic wave attenuation, velocity and piezoelectric voltage in these composites was performed over a temperature range from 300 K to 420 K using an automatic ultrasonic pulse-echo method. The temperature dependences of ultrasonic velocity and attenuation showed anomalies attributed to the glass transition temperature Tg and Curie temperature Tc of the polymer matrix.