Abstract: The aim of the present study was to identify the pathogenic bacteria associated with piglets diarrhea prevailing in pig farms of Anhui Province, and to reveal the molecular mechanism of their muhidrug resistance. Nine strains isolated from the liver samples of dead piglets with diarrhea were subjected to selective culture using MacConkey medium; the genomic DNA of the isolates was extracted and used to amplify 16S rDNA by PCR, and the amplified product was sequenced; in order to identify the isolates to genus, the 16S rDNA sequences of the isolates were deposited to NCBI and compared with the published sequences in GenBank; the susceptibility of the isolates against antimicrobial agents was assessed by disk diffusion method; the presence of muhidrug resistance gene AcrA among the isolates were screened by PCR. The results showed that the rose-coloured colonies with moderate size were observed in MacConkey medium, which was in accord with the growing characteristics of Escherichia coli （E . coli） in MacConkey medium; the 16S rDNA sequences of the nine isolates had I〉99.0% similarity with the previously reported 16S rDNA sequences of E. coli in GenBank, indicating that the isolates were identified as E. coli; the nine isolates exhibited different degrees of resistance to twelve antimicrobial agents, and the higher resistance to amikacin, spectinomycin and chloramphenicol was observed; all of the isolates were AcrA gene positive. The combined data suggest that the muhidrug resistant E. coli was the etiological agent of piglets diarrhea in pig farms of this region and enough attention should be paid to the infectious diseases caused by the isolates in clinical therapy.