Abstract: Organic acids in perry and pear vinegar were determined by using reversed phase HPLC, and influence of fermentation conditions on organic acids during brewing process of pear vinegar was studied in this paper.The results showed that: Saccharomyces cerevisiae could metabolize organic acids in pear juice.Compared with pear juice, the contents of oxalic acid and quininic acid in perry decreased, and the content of lactic acid and succinic acid in perry increased. In perry, acetic and succinic acids increased, and malic, lactic and quininic acids decreased when ethanol fermentation temperature increased. Acetic acid bacteria had the ability to metabolize organic acids of pear vinegar. Citric acid was consumed and tartaric acid was produced during acetic acid fermentation. In pear vinegar, tartaric, quininic, shikimic, succinic acids increased as acetic fermentation temperature increased.Acetic fermentation temperature hardly influenced the content of malic and oxalic acids in pear vinegar.The style of acetic acid fermentation influenced the metabolism of organic acids in pear vinegar with acetic acid bacteria.