Abstract: Sake yeast is the key microbial in the process of sake fermentation.The alcohol from sake brewing plays a toxic role in the growth and metabolism of yeast cells, which inhibits the increase of alcohol production.Therefore, it is necessary to investigate the alcohol tolerant mechanism of sake yeast for selecting and breeding of yeast strain with high ethanol yield and improved ethanol tolerance.The ethanol-tolerance mechanism of sake yeast related with cell wall, cell membrance, heat shock proteins, reserve carbohydrates, amino acid were reviewed, and the reasons for high alcohol yield and relatively low alcohol tolerance of sake yeast on the basis of cell physiology were analyzed in the paper.