Whether animal experiments can proceed( progress) smoothly is closely related to the quality of the laboratory animals． It is required by our country that the SPF level laboratory mice must be excluded from 11 kinds of virus，nevertheless，the microorganism carried by the themselves can still interfere the result of the experiments． Murine Norovirus was isolated from the accidental died mice，which can induce inflammation and even death in the immunodeficient mice． The reports on murine norovirus virus are still relatively infrequent in domestic，understanding of it's pathogenicity and the influence on the experiment is still not entirely clear． In this paper，we will mainly introduce the discovery，hazards，detection and pathogen features of the Murine Norovirus，then give advices so that we can understand MNV and control the spread of the virus better．