Two new species of the genus Craniospermum Lehm. (Boraginaceae Juss.). from Mongolia are described. The morphological and ecologo-coenotical peculiarities of the new species C. desertorum Ovczinnikova et A. Korolyuk from the sect. Leucolachnos Ovczinnikova and its distinctions from C. canescens DC., and new species C. pseudotuvinicum Ovczinnikova et A. Korolyuk from the sect. Diploloma (Schrenk) Popov and its distinctions from C. tuvinicum Ovczinnikova are considered. The new localities of C. mongolicum I.M. Johnst. and C. echioides (Schrenk) Bunge are indicated and the description of plant communities with their participation is given.Key words: Boraginaceae, Craniospermum, new species, Mongolia.