Evolution of the odor-active volatile compounds of Pixian-douban and its aroma characteristics during different fermentation phases were analyzed by gas chromatography-mass spectrometry （GC-MS）， gas chromatography-olfactometry （GC-O） and quantitative descriptive sensory analysis in this study. The results showed that 36 odor-active volatiles were identified in Pixian-douban， which endowed the product with many aroma characteristics like alcohol， sour， floral， fruity， caramel-like， burnt， miso-flavor and pungent. Furthermore， partial least squares regression model （PLSR） was used to correlate those aroma characteristics with odor-active volatiles. The results showed that alcohol had the strongest correlation with 2-methyl-1-butanol， sour was closely related to acetic acid， floral mainly came from benzene acetaldehyde and phenylethyl alcohol， fruity was correlated with ethyl acetate， ethyl isovalerate， 2-methylbutyric acid and benzene acetaldehyde， miso-flavor was mainly related to 3-methylthiopropanal， furfural and tetramethylpyrazine， while caramel-like might be formed by 2-methylbutyraldehyde， guaiacol， ethyl benzoate， HDMF and HEMF. The research could provide some theoretical information for improving the aroma characteristics of Pixian-douban.