In this paper, 1-3 composites based on Pb(In1/2Nb1/2)-Pb(Mg1/3Nb2/3)-PbTiO3 (PIMNT) single crystal and high-temperature epoxy were fabricated with various volume fractions of PIMNT single crystal ranging from 0.4 to 0.9. The electrical properties were studied as functions of PIMNT volume fraction and temperature, and it revealed that the nature of ultrahigh electromechanical coupling coefficient (0.82-0.93) and low acoustic impedance (17-19 MRayl) of the composites can be retained within a wide temperature range from room temperature to 185 degrees C. Single element ultrasonic transducer using the PIMNT 1-3 composite was fabricated and characterized as a function of temperature. It was found that the transducer can still work normally at high temperatures, such as 165 degrees C, possessing a bandwidth of 95% and insertion loss of -27 dB. (C) 2011 American Institute of Physics. [doi:10.1063/1.3583746]