Abstract: In order to identify each pair chromosomes of Allium cepa L．，We used a simplified fluorescence in situ hybridization technique to localize the satellite DNA loci in metaphase cells of Allium cepa L．The resulting hybridization patterns enabled all onion chromosome pairs to be identified．Chromosome 6-C is all acroeentric chro．mosome． Unlike the others，it has only one main locus at the end of its long arf1．Every pair of the whole chromosome8 has its own special spotting pattem，by which the 8 pairs of onion chromosomes earl be evidently identified．Thus，we made karyotype analysis ofthe genome．AC—SAT-DNA is a good probe for A．cepa L．ehro ana1．ysis．

Key words: Allium cepa L．, Chromosome, Satellite DNA, FISH, type