We have developed a mass mating method using the spore suspensions of homothallic yeasts of Saccharomyces cerevisiae in combination with dominant selective drug resistance markers, Tn601(903) against geneticin and A UR1-C against aureobasidin A for the selection of the hybrids. To examine the effectiveness of these markers in the mass mating method, each marker was introduced into a homothallic wine yeast. Using a mixed culture of spore suspensions from the resultant transformants, many hybrids were screened by the drug resistance markers. This method is more practical than the spore-to-spore mating method because it does not require the use of a micromanipulator and many hybrids are obtained at one time. The resultant hybrids could be utilized for industrial brewing because plasmids, which are used to confer resistance markers, are easily eliminated from the hybrids by cultivation in a medium without drugs. We propose that the mass mating method using spore suspensions in combination with dominant selective geneticin-and aurcobasidin A-resistance markers is useful for the selection of hybrids from industrial homothallic yeasts.