Basing on the discovery that formic acid can inhibit the cytochrome oxidase which is located at the end of mitochondrial respiratory chain,and low concentration of formic acid can lead to the rapid outbreak of the reactive oxygen species which can kill yeast cells further,factors affecting the production of reactive oxygen species in Saccharomyces cerevisiae cells were studied.Effects of cell age,low-temperature,reducing agents pretreatment,and mitochondrial ATPase gene mutation to formic acid toxicity were analyzed.The results show that formic acid resistance of Saccharomyces cerevisiae is closely related to mitochondrial activity,reducing mitochondrial activity by mitochondrial mutation can enhance cellular resistance to formic acid.