Abstract: This is the third report of chromosome numbers of Umbelliferae after 1981 and 1985, which deals with 24 species and varieties of 15 genera including 2 endemic genera and 10 endemic species, and most of them are distributed in southwestern China. Of them, 18 counts are newly reported. The taxonomic significance is discussed in relation with their basic numbers, translocation heterozygote and polyploids. It is considered that polyploids are wide-spread in Hydrocotyle L. 4, 6, 7, 8 are the basic numbers of Bupleurum L. which provides the cytological evidence for further study on their evolutionary process. n=9 and 10 occurrespectively in two different sections of Pimpinella L. and their basic numbers may be used for classification at the section level. The ring formation of four chromosomes at diakinesis of Heracleum henryi Wolff reveals that translocation heterozygotes is one of the factors in specific differentiation of Umbelliferae.

Key words: Umbelliferae, Chromosome numbers