The dielectric behavior of a series of ferroelectric side-chain liquid crystalline polysiloxanes containing 1-3 oligooxyethylene units as spacers, and 4-(S)-2-methyl-1-butyl[[(4-hydroxy-biphenyl-4’-yl)]carbonyl]oxy] benzoate or 4-(S)-2-methyl-1-butyl[[(4-hydroxy-biphenyl-4’-yl)carbonyl]oxy]-3-fluoro benzoate side groups was studied by broadband dielectric spectroscopy. The increase of the spacer length, and incorporation of a strong dipole moment fluoro-substituent into the mesogenic group, resulted in a decrease of the relaxation activation energy and an increase in the intensity of the relaxation. Moreover, the relaxation peak of the Goldstone mode has only been observed for the FLCP with a lateral fluoro-substituent. The relationship between the thermal dynamic behavior and chemical structure is discussed in detail. Furthermore, analysis of the dielectric relaxation behavior of these FLCPs showed that the molecular relaxations could be described by the Cole-Cole equation.