The influence of non-ionic surfactants on the stability of polysiloxane anionic latices towards electrolytes was studied. The critical coagulation concentration of magnesium chloride in the diluted latices greatly increased by incorporation of dodecyl polyoxyethylene glycol monoether C12H25 (OCH2CH2)mOH (n= 6.3

C12E6.5). The surface chemical properties of the latices and the composition of the surfactants on the particle surface revealed the synergy between C12E6.3 and dodecylbenzene sulfonic acid. They form a mixing interface film. The stabilization of C12E6.3 towards electrolytes can be explicated according to the DLVO theory.