Interspecific F1 hybrid (2n=30-36) was produced for the first time by artificial cross pollination between Chrysanthemum boreale (2n=18, diploid) and C. vestitum (2n=54, hexaploid). The analysis of fluorescence in situ hybridization (FISH) in the 45S and 5S rDNA sites showed that the F1 hybrid had six and eight signals respectively (instead of eight and six signals of the 45S and 5S rDNA sites respectively) were shown in the F1 hybrid perhaps due to translocation and recombination. Genomic in situ hybridization (GISH) distinguished respective parental chromosomes in the F1 hybrid chromosome complement and showed that at the time of using the biotin labeled probe of C. boreale showed approximately 9-yellow-green-colored chromosomes were hybridized with the probe of C. boreale, might related to C. boreale, 18 orange-colored chromosomes might have a commone chromosome homology between C. boreale and C. vestitum, while the other 9 red-colored were not hybridized chromosomes with the probe and could be of C. vestitum.