Based on the composite dielectric polarization theory, dielectric permittivity, dissipation factor and loss angle tangent of hydrated paraffin versus temperature and power supply frequency were analyzed. The effect of different water contents in paraffin on its dielectric characteristics was also studied. The more the water content in hydrated paraffin, the greater the dielectric parameters, dissipation factor can reach 1.48 when the water contents was 15%. They can provide references for theoretical researches and industrial applications on removal of paraffin that condense on the interior walls of oil pipes in oil extraction by electric heating method.