Abstract: Chromosome numbers andmorphology of 4 genera of Liliaceae ( s. str .) from HengduanMountains of southwestern China were studied. Almost all populations in Lilium were diploid, with 2 n = 24 , except that populations of L. tigrinum were found triploid, with 2n = 36. All taxa in Fritillaria investigated were diploid , with 2n = 24 and the secondary constrictions were obvious and abundant. Diploid and triploid exist in different populations of Notholirion bulbuliferum, with 2n = 24 and 2n = 36, and there was one population contained both ploidy types. For Lloydia , only one taxon Lloydia tibetica
was studied, with 2n = 23. All taxa studied were collected in Hengduan Mountains, and the differences among these genera were obvious, which would contribute to the future taxonomic study . The karyotypes of L. matangense and Lloydia tibetica were documented for the first time.

Key words: Chromosomes