Yeast Saccharomyces cerevisiae is the main microorganism in the production of liquor,but fermentation environment is always disadvantageous to its growth.It is always exposed to several stress conditions including low pH stress resulting from weak organic acid.Yeast cells have developed a common response to environmental adverse conditions,but there are some differences among different stress.Researches on weak organic acid stress mechanism of Saccharomyces cerevisiae in recent years are reviewed in this paper,including gene expression,transcript expression and protein expression.ATP binding cassette transporter Pdr12 and its transcription factor War1p,HOG-MAPK pathway,FPS1 aquaglyceroporin,plasma membrane H+-ATPase,superoxide dismutase(SOD),catalase(CAT) and interaction of weak acid stress with other stress are all discussed.We hope it could provide certain reference for better research on weak acid stress mechanism of Saccharomyces cerevisiae.