Abstract: The karyotype of Yunnan hare (Lepus coomus)has been studied by banding techniques (G-，C-banding)and silver staining． The number of diploid chromosome is 48,autosomes consist of 6 pairs of metacentrics， 5 pairs of submetacentrics， 10 pairs of subtelocentrics and 2 pairs acrobentrics． X is a larger submetaeentric．And very faint secondary constrictions is found on pairs 17，19．21．
The G-banded， C-banded and silver-stained karyotypes have been observed． The chromosomal homologies of genus Lepus are high by comparing their G-banded karyotypes．The certromeric heterochromatin is found in all chromosomes except Nos．9，14，l6， 20，whereas the centromeric C-bands of Nos．13， 15，18 are very fanitly stained．The sequential studies of conventional and silver stained karyotypes show Ag-NORs at the faint secondary constrictions of Nos． 17， 19，21． The Polymorphism of Ag-NORs of No．21 is found．And the karyotype evolution of Leporides has been discussed by comparison with other species．

Key words: Yunnan hare, Banding patterns of chromosomes, Karyotype evolution

摘要： 本文以染色体分带技术(G-，C-带和银染色)，对云南兔(Lepus comus)的核型进行了观察分析。结果表明t：2n=48，NF=88。常染色体由6对中着丝粒染色体， 5对亚中着丝粒染色体，10对亚端着丝粒染色体和2对端着丝粒染色体组成；X染色体为亚中着丝粒染色体。除少数几对染色体(Nos．9，14，16，20)着丝粒C-带呈阴性外，其余均呈阳性或浅染，但异染色质的含量差异较大。Ag-NORs的数目为5-6个，分别位于Nos．1 7，19，21。通过与兔科其它属种核型的比较，对其染色体进化作了讨论。

关键词: 云南兔, 染色体带型, 核型进化