Electro-optic and dielectric studies have been carried out on two ferroelectric liquid crystalline materials: namely, the commercial mixture possessing low spontaneous polarization and pure material with high spontaneous polarization on cells with planar alignment. The calculated values of spontaneous polarization, response time and rotational viscosity were found similar to 240 nC/cm(2), 20 nC/cm(2), 1600 mu s, 500 mu s, 230 kg/ms and 19 kg/ms for high and low polarization ferroelectric liquid crystalline materials, respectively. For the ferroelectric liquid crystal with high polarization, the effect of temperature, frequency and bias field on the dielectric properties have been studied and the obtained results were compared to those obtained on the ferroelectric liquid crystalline mixture with low spontaneous polarization. (C) 2010 Elsevier B.V. All rights reserved.