Objective:To investigate the polyadenylation of mRNA in E. Coli. Methods: The mRNA of E. Coli was enriched from the total RNA with oligo(dT)-cellulose, prior to reverse transcription using oligo(dT)18as the primer. Double-stranded cDNA was subsequently synthesized, which was subjected to digestion with Sau3A I to produce multiple gene fragments for ligation with the adapters. PCR was carried out in 10 groups according to 10 different pairs of the selective primers, and the PCR products were then cloned into T-vectors. Results: More than 100 gene fragments had been cloned, 30 of which were sequenced. Conclusion:Polyadenylation of E. Coli mRNA may not be a biochemical curiosity but a general attribute of bacterial mRNA.