Energetic electrons measured by the NOAA-6 satellite are compared with LF whistler-mode signals transmitted from a Decca station (Biei, L = 1.54, f c = 85.725 kHz), Japan, and measured in the magnetic conjugate area, Australia. The simultaneous satellite measurement of energetic electrons indicated the considerable enhancement of energetic electron fluxes more than 30 keV in the low L-shell region below ∼ 2 at the maximum depression phase of D st, and the subsequent abundant fluxes of trapped electrons more than 30 keV on 1 day and occasionally 2 days after the maximum phase. Associated with magnetic disturbances, the LF whistler-mode signals were intensified. However, the intensity increase of the signals was not so large at the maximum phase, which may be attributable to an ineffective wave growth caused by a rather isotropic pitch angle distribution of energetic electrons. The intensity increase was the largest one day after the maximum phase, due to the wave growth caused by cyclotron resonance interactions with trapped electrons. Also associated with magnetic disturbances, the frequency of enhanced LF whistlermode signals shifted, which is caused by the drift of whistler ducts due to the magnetospheric electric fields penetrating into the low-latitude magnetosphere. Therefore, the penetration of storm-related energetic electrons and magnetospheric electric fields into the low L-shell region below ∼ 2 may be deduced from ground-based conjugate measurements of resonant waves.