The electric light scattering of aqueous oxide suspension in the presence of sodium carboxymethylcellulose (Na-CMC) was investigated. The electro-optical effect in the kilohertz frequency range was found to decrease because of the polyelectrolyte adsorption, contrary to the strong increase of the effect in the range of particles rotation (at hertz frequencies). The counterion mobility decrease due to condensation in the polyelectrolyte vicinity was supposed to be responsible for the relaxation frequency shift of the effect to the low-frequency side. The addition of salts (NaCl and CaCl2) to the stabilized suspensions was shown to change the ratio of high frequency to low frequency effects-the first one was seen to increase in contrast to the second. In the presence of salts, the polyelectrolyte charge shielding and counterions mobility increase were found to be different for monovalent and divalent ions, which could be attributed to the specific interaction of Ca2+ with Na-CMC.