To establish anoptimizedmethodcombination, which was sensitive, accurate and rapid for Escherichia coli enrichment and DNA extraction, so that we can use a real-time qPCR method (TaqMan probe) for detection and enumeration of Escherichia coli in drinking water.MethodsIn membrane filtration-elution step, the bacteria particles were concentrated by three different methods, and the recovery of E.coli was estimated quantitatively by Enumerating CFU on plate agar．In DNA extraction step, the genomic DNA were extracted with four different methods, and the TaqMan PCR assay was used to amplify and measure the recovery of the extracted DNA. ResultsThe recovery of E.coli eluted from the membrane was 76%-93% by using C-method (filtrating with Staph.epidermidis+vortex washing+glass rodscraping). Of the four extraction protocols, Triton-100and beads extraction method had the same linear range (10⁰-10-5), r²:0.998and 0.999respectively. However, the first method had significantly lower cost and time consuming. The recovery of E.coli from water was 79.7%-104.0%, and the sensitivity of qPCR was 1cfu/ml for the whole processing using the optimal methods for DNA extraction.ConclusionThe optimal methodcombination (C method+TritonX-100method) was rapid, accurate and economic for E. colienrichment from water and DNA extraction．