Candida cyclindracea lipase (CCL) was added to "sodium dodecyl sulfonate (AS)/n-butanol/n-octane/n-octane" water-in-oil microemulsion to catalyze the hydrolysis of ethyl mandelate and the esterification of alpha-bromopropionic acid with n-butanol, respectively. The catalytic activity of CCL in the above microemulsions was higher than that in the traditional oil/water biphasic systems. After hydrolysis for 48 h, the conversion rate of the reaction reached 90% and S-mandelic acid, [alpha]D20-149.8 (C10; H2O), optical purity ca. 97%, was isolated. While after esterification for 6 h, the conversion rate of the reaction reached 45%, and butyl-(R)-alpha-bromopropionate, [alpha]D20 18.2 (Cl; CHCl3), optical purity ca. 99%, was obtained.