Abstract: The influences of sodium benzosulfinate (BSI), 1-phenyl-5-mercaptotetrazole (PMT) and 5-methyl-7-hydroxy-1, 3, 4-triazaindolizine (TAI) on the ionic conductivity of the microcrystals of silver halide emulsion are investigated by Maxwell-Wagner effect with the aid of dielectric loss measurement in the frequency range of 10 kHz-3 MHz.The addition of BSI (4.76-19.07 g/M AgBr) causes no drop of the ionic conductivity, whereas the addition of PMT and TAI (0.93 g/M AgBr) decreases the ionic conductivity greatly by about 2 log units and increases the conduction activation energy and surface potential by 0.12 eV. It is further shown that the iodide contained in emulsion microcrystals has a great restraining effect on the ionic conductivity decrease when TAI is adsorbed onto the microcrystals. This finding is of significance from the practical aspect.The possible explanation of the above-mentioned phenomena in ionic condutivity behaviour is presented and discussed.