The present study was carried out to clarify the chromosome numbers and karyotype of Atractylodes japonica Koidz. ex Kitam. and A. macrocephala Koidz.. The somatic chromosome numbers of two species were same; basic chromosome number x=12, and somatic chromosome numbers 2n=24. The present result of A. japonica Koidz. ex Kitam. was same to previously reports and that of A. macrocephala Koidz. was reported first in this study. Size and shape of chromosome were some different from A. japonica Koidz. ex Kitam. and A. macrocephala Koidz.. The karyotype of A. japonica Koidz. ex Kitam. was described as follows; 2n : 24 : 8L + 14M +2S : 2 Asm +2 Bm +2 Cm +2 Dst + 2 Em +2 Fm +2 Gm +2 Hsm + 2 Im + 2 Jm + 2 Km + 2 Lm . And the karyotype of A. macrocephata Koidz. was described as follows; 2n : 24 : 10L +12M +25 : 2 Am +2 Bsm +2 Csm +2 Dsm +2 Esm +2 Esm +2 Gsm +2 Hm +2 Im 2 Jm +2 Km +2 Lm . .