By paper partition chromatography (System I of King et) it is possible to separate the members of a new group of heterodianthrones isolated from the fresh roots of Rheum palmatum L. The following palmidins were separated and identified: palmidin A: heterodianthrone of aloe emodin anthrone and emodin anthrone palmidin B: heterodianthrone of aloe emodin anthrone and chrysophanol palmidin C: heterodianthrone of emodin and chrysophanol.