Abstract: The dielectric spectra of the cubic AgBr emulsions doped with Na₂S₂0₃ and Na₂S have been studied.Sodium thiosulfate which is added into AgBr emulsions acts in two ways.1, On the surface of the AgBr microcrystal, the adsorption of sodium thiosulfate is the primary factor when its concentration is lower than 1×10^-4mol/mol AgBr.In this range, the ionic conductivity of AgBr microcrystal decreases slightly with increasing concentration.The f_max of the dielectric loss curve are shifted slightly to lower frequencies, and Δ(logf_max) depend upon the condition of the AgBr microcrystal surface.2, When the concentration of Na₂S₂0₃ is higher than 1×10^-4mol/mol AgBr, it is getting predominant that the surface of the AgBr microcrystal is corroded by S₂0₃= ions.As a result of corrosion, the surface of the AgBr microcrystal becomes more heterogeneous and the distribution of the relaxation time τ of the interface polarization is broadened relatively.On the other hand, when pAg of the emulsions are increased, f_max of the samples are shifted to higher frequencies.f_max of the samples with Na₂S (<1×10-8 mol/mol AgBr) are shifted slightly to lower frequencies.When the dried samples are heated at 75℃ and 110℃ for 6h respectively, S⁼ ions diffuse slowly into the crystal lattice of AgBr, the ionic conductivity of the AgBr microcrystal increases, f_max of the samples are shifted to higher frequencies.