A method is presented for determining the Bruce and Golde (1941) model parameters of the current pulse in a lightning discharge channel from an only spherics waveform. It is based on the assumption that the frequency domain spectrum of a spherics is described as a product of a ''fast'' multiplier and a ''slow'' multiplier. The first multiplier is responsible for a ''thin'' structure of the waveform; the letter one is mainly determined by the current pulse parameters. When the distance from the lightning is known, the solution is to separate the ''slow'' multiplier from the spherics spectrum and adjust it with the modeled Bruce-Golde current spectrum by parameter variations. Numerical experiments using real spherics data demonstrate rather good results for current parameter estimations. ¿ American Geophysical Union 1994