Abstract: In this pqper, we imitate transfer functions of ultrasonic transducer under different temperature conditions according to Mason's equivalent circuit of ultrasonic transducer. The relevant experiments have been carried out. The results show that the transfer characteristic of ultrasonic transducer varies with temperature and pressure. FOr this reason, we present an approach to correctting the amplitude spectra of ultrasonic echoes acquired in different temperature and pressure environments. The theoretical simulations and the experiment results demonstrate that the approach is simple, effective and practical.