Dipolarization of geomagnetic fields had been found to occur at tailside during geomagnetic activities associated with decreasing in AL index and substorms. Based on data analysis from electric field instrument and search coil magnetometer onboard of THEMIS mission, whistler-mode waves are found at dipolarization sites near the magnetic equator around 10 RE (Earth radii) in the inner plasma sheet. Meanwhile, the electron fluxes and their pitch angle distributions are also found to vary during dipolarization period. Therefore, we study the interaction between electrons and these waves from the perspective of test particle simulation. The observed wave frequencies, amplitudes, and wave angles as well as the electron energies are adopted to implement the simulation. Observations of parameters of the waves and electrons, as well as the preliminary simulation results of changes in energies and pitch angles of electrons at different energies will be presented. We anticipate the results will be beneficial to understand the role these observed whistler-mode waves play during dipolarization periods at tailside.
