S-Ethyl-4-chloro-3-hydroxybutanoate( S-CHBE) is used as a chiral building block for the synthesis of pharmaceutical target compounds. S-CHBE can be produced by the asymmetric reduction of ethyl 4-chloro-3-oxobutanoate( COBE). In present study,the S1' gene was delivered from the NADPH-dependent carbonyl reductase gene( S1) of Candida magnoliae AKU4643 followed artificially synthesizing and codon optimizing for E. coli host. The recombinant strain BL21( DE3) / pET28a-S1 ' with S1 ' gene showed more effective expression of carbonyl reductase gene. The highest activity of carbonyl reductase was achieved 11. 49U / mg protein after induction conditions optimization. Furthermore,the asymmetric reduction of COBE to CHBE was performed using the recombinant E. coli BL21( DE3) /pET28a-S1' coupling with E. coli BL21/pET28a-gdh in an aqueous system and the enantiomeric excess( e. e.) of S-CHBE was arrived to 92. 1% and 100% respectively after 10h bioconversion without adding coenzyme NADPH or NADP+.