The invention provides a preparation method of a mice intestinal 
flora alteration ERIC-PCR (Enterobacterial Repetitive Intergenic 
Consensus sequence-based 
Polymerase Chain Reaction) 
fingerprint spectrum. The preparation method comprises the steps: moulding mice intestinal 
flora alteration caused by antibacterial-associated 
diarrhea, extracting a 
cecum content 
DNA, eliminating 
humic acid in the 
cecum content 
DNA, eliminating a PCR inhibitor in the 
cecum content 
DNA, performing ERIC-PCR amplification and native 
polyacrylamide gel electrophoresis (Native-PAGE), and comparing with a conventional 
flora analysis result so as to establish the ERIC-PCR 
fingerprint spectrum of the mice intestinal flora alteration. According to the preparation method, with a pure-series mice as a 
research object, the defect caused when a conventional bacterium culturing method is applied to the microflora analysis is solved. The preparation method can be used for 
rapid detection of the laboratory mice intestinal flora alteration, prevents the defects of complicated operation, long time consumption, large 
workload and the like of conventional bacterium separation and culturing, and is capable of accurately, rapidly and effectively detecting the mice intestinal flora distribution condition.