In orderto construct a genetic engineering phenylpyruvate reductase strain (E. coli/ppr), the expression conditions and bioconversion medium were optimized to increase the production of PLA with whole-cell transformation. A phenylpyruvate reductase-encoding gene, lpppr, was obtained by PCR from the genomic DNA of Lactobacillus plantarum and heterologously expressed in E. coli BL21 (DE3). Taking phenylpyruvic acid as the substrate, single factor and orthogonal experiments was used to optimized the induced expression and whole-cell catalysis conditions. Results showed that after inductionwith 0.5 mmol/L IPTG at 20 ℃ for 8 h, E. coli/ppr displayed the highest LpPPR activity. When phenylpyruvic acid was added up to 25 mmol/L, the product enantiomeric excess percent was over 99.9% and the final yield of PLA could reach 98.38% at 5 h under the obtained optimal catalytic conditionsas follows: temperature 40 ℃, initial pH 6.5 and 20 mmol/L glucose.