Abstract: Different concentrations of benzotriazole (BTA)solutions at pH=10.6 were used to treat samples of cubic AgBr emulsions before or after exposure for investigating effects of BTA respectively on the latent image formation or the development.Some interesting results were obtained.These were:1) That for unsensitized emulsions treated by BTA solution before exposure,a significant desensitizing effect was shown when the concentrations of BTA in solutions increased from 1?10^-5 to 1? 10^-3 mol/L,on the other hand when the emulsions treated by BTA solution after exposure,the developments were greatly enhanced;2) That for sulfur sensitized emulsions followed the same procedures as the unsensitized emulsions,a significant hypersensitization was exhibited and the hypersensitization was strikingly intensified as the concentrations of BTA in solutions increased,as a result the relative sensitivity of the sulfur sensitized sample treated with BTA solution was 4 and more times high as that of the sample for control,whereas there was slightly significant effect on developments of the exposed S sensitized sample treated with BTA solutions after exposure;3) That for S sensitized emulsions which treated first with 388 mV buffer and then with 1?10^-3 mol/L BTA solution,a remarkable hypersensitization by BTA still appeared so that it seemed to be related to the existence of Ag₂S clusters and not to Ag clusters in S sensitizing centers.

Key words: imaging process of silver halide, hypersensitization, stabilizer