This paper analyses the methods to measure degree of similarity and distance between DNA sequences based on the theory of fuzzy genomes and fuzzy polynucleotide spaces. all of sample data for the experiments are virus genome taken from NCBI (National Center for Biotechnology). the experiments scenarios measure degree of similarity and degree of difference between H5N1 virus and H5N1 virus, between H5N1 virus and other influenza virus, and between H5N1 Virus and other virus. the result shows that viruses with same type have high degree of similarity and low degree of difference. the measurement cannot classify subtype in influenza virus. however, the measurement of influenza virus with other kind of virus has relattively low degree of similarity and high degree of difference. this result creates a possibility to classify influenza virus and other by using this method.