Abstract: Karyomophological studies on the three species of genus Siegsbeckia from Kunming of China were carried out by root tips squash method. The three species were found to have the same chromosome numbers 2n =30, basic chromosome number in this genus was x=15, belonged to diploid. The morphology of the resting nuclei and that of the mitotic prophase chromosomes are very similar among the three species and can be classified as complex chromocenter and grad- ual types respectively. At mitotic metaphase, their karyotype formulas and karyotype asymmetry were showed as follows.

Key words: Compositae