Ultrasonic diagnostic equipment utilizing the pulse reflection method is widely used in the field of medicine. For evaluation of the equipment and for studies on bioeffects of ultrasound, it is necessary to know the sound field generated by the equipment. This paper reports on wide frequency range miniature hydrophones for the measurements of pulse ultrasonic fields of several MHz range. Construction of the developed hydrophones, experimental data on their performance and measured results of sound fields obtained by the hydrophones are presented.