From the cells of 142 strains of the genera Rhodotorula, Cryptococcus, Sporobolomyces, and Rhodosporidium, coenzyme Q (Co-Q) was extracted and partially purified by thin-layer chromatography. The type of Co-Q was mainly determined by paper chromatography. The Co-Q system of these organisms, which were considered to have a phylogenetic relationship to Basidiomycetes, was characterized by the dominant distribution of Q10. An exceptional distribution of Q9 was found in several strains of Rh. glutinis whose perfect stage is Rhodosp. toruloides, Rh. glutinis var. rufusa, Rh. lactosa, Cr. neoformans var. uniguttulatus, Cr. luteolus, and Rhodosp. malvinellum. Rhodotorula infirmo-miniata was the only species with Q8. The genus Rhodosporidium was divided into two groups composed of Q10 and Q9 possessors on the basis of their Co-Q system. These results are discussed in connection with other criteria such as serological characteristics and DNA base composition.