Abstract: The electric-field-radiosonde for thunderclouds is made. A long wire with points at both ends is employed as its inductor and a FM-AM telemetering system is used. The FM-AM system consists of two vaccum tubes 2п1п. One is used for frequency modulator and another for transmitter. The transmitting frequency is about 85 MHZ. An antiinterference circuit is employed in the receiving equipments, thus the interference caused by non-overhead lightning can be removed. The results of five soundings obtained in thunderclouds are given and analyzed primarily.