The effect of mixed micelles (polyethylene glycol-CTAB cationic surfactant, shortchain alcohol-SDS anionic surfactant) on the alkaline hydrolysis of normal aliphatic esters has been studied at 20 and 30°C with the method of difference of thermogram-area of thermokinetics in this paper. The results indicate that this reaction is inhibited by the single and mixed micelles. The mixed micelles of PEG and CTAB exhibit a greater effect of inhibition on the reaction than those do in single PEG or CTAB systems. The extent of inhibition for the reaction in the mixed micelles of SDS and alcohol is less than that in single SDS micellar solutions. The critical micellar concentrations of the corresponding systems have also been measured with the conductivity method in this paper.