The polarization reversal currents of a ferroelectric liquid crystalline polymer were measured. The shape of the current signal was similar to that of low molecular weight ferroelectric liquid crystals. It was found from our calculations that the shape of the current signal was independent of the polydispersity of the polymer. In ferroelectric liquid crystalline polymers, components having different molecular weights respond cooperatively with each other to the applied voltage. From the results of our simultaneous measurements of transmittance and polarization reversal current, the dipole unit and the core moiety in the side chains appear to move in a body.