The absorbance of crystal violet (CV) in a se-ries of aqueous solutions and a series of sodium bis(2-ethyl- hexyl) sulfosuccinate (AOT)/isooctane/water microemulsions has been determined. Association models have been used to analyse the experimental data to obtain the association con-stants of CV and AOT in the above two media. It was found that about up to 57% CV was associated by AOT in AOT/ isooctane/water microemulsions, which reduced the reaction rate of alkaline fading of crystal violet in the microemulsions. The absorbance of crystal violet (CV) in a se-ries of aqueous solutions and a series of sodium bis (2-ethyl- hexyl) sulfosuccinate (AOT) / isooctane / water microemulsions has been determined. Association models have been used to analyze the the It was found that about up to 57% CV was associated by AOT in AOT / isooctane / water microemulsions, which reduced the reaction rate of alkaline fading of crystal violet in the microemulsions.