Emulsion liquid membranes (ELMs) were first applied to extraction of succinic acid in simulated media (feed solution) where concentration of succinic acid was as high as that in an actual fermentation broth producing succinic acid. In order to develop an ELM system where a high degree of extraction of succinic acid can be obtained, in the beginning we investigated the effects of several operating variables of the ELM system, i.e. surfactant composition in the membrane phase, stripping agent type and its concentration in the stripping phase and feed solution type, on its degree of extraction for a low initial succinic acid concentration, which was sensitive to the operating variables. The optimal values of the operating variables were used in the ELM system with a high initial concentration of succinic acid. Finally, extraction of succinic acid in the feed phase with the high initial succinic acid concentration was carried out varying 1-octanol and Amberlite LA-2 concentrations in the membrane phase, initial Na(2)CO(3) concentration in the stripping phase, and initial volume ratio of emulsion phase to feed phase. Under a specific operating condition, the degree of extraction of succinic acid was as high as 98%, and its enrichment ratio reached about 1.3. (C) 2011 Elsevier B.V. All rights reserved.