The relationship between Schwanniomyces occidentalis CBS 2863 (formerly castellii) and CBS 1153 (formerly alluvius), and their variety persoonii was examined at alpha-amylase gene level. Using Sch. occidentalis alpha-amylase gene as probe, Sch. occidentalis alpha-amylase gene homologues were obtained from Sch. occidentalis CBS 1153 and Sch. occidentalis var. persoonii. The restriction analysis of these homologues showed that the restriction enzyme sites between Sch. occidentalis CBS 2863 and CBS 1153 was identical but different between these strains and Sch. occidentalis var. persoonii.