Interdelta fingerprinting has been carried out for Saccharomyces strain typing by using 45 Saccharomyces isolates from spontaneous fermentation of Cabernet Sauvigon in Ningxia. The dynamic changes of the Saccharomyces cerevisiae strains were observed, which can provide an approach for better control of the fermentation process. The result revealed that 5 genetic patterns were distinguished by interdelta finger-printing among the total Saccharomyces isolates. The genetic pattern I to V accounted 71%、13%、9%、5.0%、2.0% respectively for the proportion of the total Saccharomyces isolates. Therefore, the genotype I was the dominant strain during the fermentation. Moreover, the influences on the genotype, the number and the pro-portion of S. cerevisiae strains by sulphur dioxide added before fermentation were also demonstrated in this study.