Main purpose of this thesis is to analysis of Escherichia coli and Shigella species in the Freshwater Environment of Bangladesh by PCR-DGGE. Other objectives are Recovery of the environmentally stressed, injured and starved Shigella spp. and E. coli from freshwater environment. Here also Statistical analysis to correlate the occurrence of different phyla, genes and bacterial genera with one another. Finally identification of the community of E. coli and Shigella spp. by assessing the sequencing results of the DGGE bands, results of PCR assay for specific virulent genes and the outputs of statistical analysis.