Abstract: Chromosome examination was carried out in 30 medical plant species native to Xinjiang in 14 families, ten of which are traditional medical plants of the minority nationalities in the region, the karyotype analysis was also carried out in some species. Karyotype formulae are 2n=12=10Lm+2S_st^SAT for Nigella glandulifera, 2n=16= 2m+12sm+ 2st for Trollius chinensis, 2n= 16 =8m + 8sm for Astragalus membranaceus, 2n=16=10m 6 sm for Astragalus mongholicus, 2n=16=8 m+8 sm for Catharanthus roseus. The chromosomal numbers of the others are as follows: Dianthus chinensis, 2n=30, Vaccaria pyramidata, 2n=30, Cassia occidentalis, 2n=26, Psoralea corylifolia, 2n=22, Peganum harmala, 2n=22, Acanthopanax trifolitus, 2n=46, Anethum graveolens, 2n=22, Foeniculum vulgare 2n=22, Trachyspermum ammi, 2n= 18, Agastache rugosus, 2n= 18 Dracocephalum moldavica, 2n= 10, Leonurus heterophyllus, 2n=20, Ocimum basilicum, 2n=48, schizonepeta tenuifolia, 2n=24, Atropa belladonna, 2n=60 Nicandra physaloidea, 2n=20, Solanum surattense, 2n=24, Scrophularia ningpoensis, 2n= 90, Plantago insularis, 2n =8, Gardenia jasminoides, 2n =22, Platycodon grandiflorus 2n= 18, Cichorium intybus, 2n= 18, Saussuea involucrata, 2n=32, Silybum marianum, 2n=34, Vernonia anthelmintica, 2n=20. The kar-yotypes of 8 species are reported for the first time.