Abstract: It is of practical and theoretical importance to retrieve incloud lightning discharge parameters from far radiation fields,since these parameters are inaccessible by direct measurements.In this article a simple technique is presented to derive these parameters from remote electrom agnetic field measured at a single site based on Transmission Line Model.The time for the current to travel from the bottom to the top of the transmission line channel is only of several microseconds,the transmission line current tends to produce the remote electromagnetic field in VLF/LF band approx imately as the same way as the current dipole does,that is,the field is linear to the current derivative multiplied by the channel lengt h.Therefore by recording the remote electromagnetic field and making the time integral one can obtain the full waveform of the current movement (current mult iplied by channel length),except that its rise would be slightly broadened.The current waveform will be further extracted from the current movement waveform under assumption of the channel length.Furthermore,the time for the current to travel from bottom to top of the channel can also be estimated from the amplitude ratio of the remote radiation field to its time integral,which will help to estimate alternately the traveling velocity of the current (assuming the channel length) or the channel leng th (assuming the current velocity).This method provides a potential tool to evaluate incloud lightning discharge parameters from lightning bipolar radiation fields.