Intergeneric or intraspecific protoplast fusion between Saccharomyces cerevisiae X-2180-1A, Candida pseudotropicalis ATCC 8619 and CBS 607 was attempted to produce ethanol from lactose containing materials. Teh intergeneric fusion frequency between Saccharomyces cerevisiae X-2180-1A (ade rho) and Candida pseudotropicalis CBS 607 (his met) was $1.0 imes 10^{-5}$. These values exhibited approximately 2-3.5 fold increase when compared with fusion frequency obtained without the treatment of bovine serum albumin, myoinositol and ergosterol, suggesting that these compounds may improve intergeneric of intraspecific protoplast fusion. Nuclear fusion appears to occur in fusants between intergenera(S. cerevisiae+C. pseudotropicalis) and intraspecies (C. pseudotropicalis strains) as strongly suggested by DNA content, nuclear staining, comparison of survival rate to UV light and isolation of recombinants after mitotic segragation. It was also found that alcohol production from intraspecific hybrids was somewhat increased when compared with that from their parents.