Abstract: In order to investigate the impact of malic enzyme on the capacity of fatty acid synthesis about prokaryotes, the MaeB gene encoding NADP ME was amplified from E.coli K-12 genome by PCR and inserted in the vector pET30a-T to build recombinanted plasmid pMX20. Malic enzyme was overproduced by E.coli BL21 (DE3) harboring pMX20 under the condition of IPTG induction. The results of fermentation indicated that overexpression of malic enzyme in E.coli would have influence on the capacity of fatty acid synthesis, and meanwhile, the total lipids in recombinanted cell was 4 times to E.coli BL21 (DE3) under the condition of adding appropriate substrate of malic acid (about 197.74mg/g) , and the yield was 1.89%. These results also showed that the recombinanted strain MX20 was useful and had certain development prospects which would provide an excellent strain for fatty acid production.