The phase behavior of the microemulsion for the quaternary system of the alkylethoxyglucoside (AEG) / alkylethercarboxylate (AEC) / alcohol / acetochlor / water has been studied with ternary phase diagram, the effects of different alcohols and different alcohol-contents on acetochlor microemulsion were discussed and transformation of microstructure of the acetochlor microemulsion was studied by means of conductivity measurement. The results show that the area of microemulsion region decrease as the carbon chain of alcohol molecules increasing, and the liquid crystal region form and increase. When alcohol is n-butanol, the biggest microemulsion region area is corresponds to a certain content of n-butanol.