In　the　aqueous　medium　the　asymmetric　reduction　of　2-octanone　with　Baker＇s　yeast　FD-12　was　inhibited　severely　by　the　substrate　and　the　product　at　higher　concentrations,　which　resulted　in　a　low　yield　and　a　low　e.e.　value　of　the　object　product　(S)-2-octanol.　Seven　water/organic　solvent　biphasic　systems　were　assayed　in　this　work.　FD-12　showed　the　best　tolerance,　catalytic　activity　and　enantioselectivity　in　the　water/n-dodecane　system　among　the　biphasic　systems　assayed.　The　metabolic　activity　retention　(MAR)　and　viability　of　FD-12　in　the　n-dodecane　containing　system　were　98%　and　91.6%,　respectively.　The　influence　of　the　volume　ratio　Vaq/Vorg,　temperature,　pH　value　and　the　substrate　concentration　on　the　yield　of　2-octanol　and　the　e.e.(S)　value　was　investigated.　Under　the　optimum　conditions　(in　the　water/n-dodecane　biphasic　system,　Vaq/Vorg　20/5,　pH　8.0,　32　°C,　2-octanone　concentration　500　mM),　the　final　concentration　of　2-octanol　and　the　e.e.(S)　value　reached　105.60　mM　and　89.38%,　respectively,　after　96　h　reduction.　The　water/n-dodecane　biphasic　system　with　FD-12　was　advantageous　for　the　production　of　(S)-2-octanol　of　high　final　concentration　and　high　e.e.(S)　value.　©　2006　Elsevier　Inc.　All　rights　reserved.