Abstract: The somatic cells of 12 taxa of the genera Nomocharis, Lilium, Fritillaria and Cardiocrinum from north-western Yunnan were karyomorphologically studied. The 12 taxa are similar to each other in chromosomal morphology at the resting nucleus stage, which belongs to the complex chromocenter type. They are also similar to each other in morphology of mitotic prophase chromosomes, which belongs to the interstitial type. Their chromosome numbers are all 2n = 24, and centromeric terminalization values range from 79.9- 82.2%. The above results show that the four genera have close relationships. These 12 taxa, however, exhibit some similarities and differences in the position of secondary constrictions seemingly showing the karyological characters of each genus in the area. Firstly, on m(sm)-chromosomes, secondary constrictions close to centromeres appear stable in one of pairs in both Nomocharis( 6 taxa) and Lilium (4 taxa); In Cardiocrinum giganteum, they were found distant from centromeres on short arms in one of pairs; None was observed in Fritillaria cirrhosa. Secondly, on st (t)- chromosomes, remarkable secondary constrictions were generally found on long arms in Nomocharis, C. giganteum, F. cirrhosa and the high mountain habitants of Lilium, such as L. souliei, while they were always observed on short arms in L. nepalense, L. taliense and L. brownii, which grow in the lower altitude region. So the Nomocharis and high mountain members of Lilium have similary distribution of secondary constrictions, and theyare considered to be most closely related.

Key words: Liliaceae, Nomocharis, Lilium, Cardiocrinum giganteum, Fritillaria cirrhosa, Karyotype