Eight strains of Saccharomycopsis species were examined for their partial base sequences of 18S and 26S rRNAs. The base sequences on the fingerprint segment showed three kinds of ACUAU, UCUAU, and AUAU. In the partial base sequences (positions 1451-1618, 168 bases) of 18S rRNA, all the strains of Saccharomycopsis species examined had 1-0 base difference except for the strains of Saccharomycopsis fibuligera (base differences, 5-4). In the partial base sequences on the positions 1611-1835 region (225 bases) of 26S rRNA, however, S'copsis vini had 15-11 base differences. The other species had 7-2 base differences. In the partial base sequences on the positions 493-622 region (130 bases) of 26S rRNA, the calculated percent similarities were 62-77. Discussion was made phylogenetically and taxonomically, especially on the separation of S'copsis fibuligera (identical to Endomyces fibuliger) from the genus Saccharomycopsis.