Besides yeast and lactic acid bacteria (LAB), acetic acid bacteria (AAB) are dominant bacterial group in Jiaozi and many sourdough starters. In this study, we investigated the influences of AAB on the properties of sourdough and steamed bread. The results showed that the AAB strain (Acetobacter A3) could improve the rheological properties of the sourdough, increase the specific volume and soften the texture of the steamed bread. Moreover, the AAB strain could also improve the aroma profile of steamed bread, according to the results of SPME-GC-MS.