Microbial diversity of a traditional Jiaozi was studied by isolation and purification and 16S rDNA Clone Library technique and Amplified rDNA Restriction Analysis (ARDRA) and Biolog carbon utilization analysis. The dominant bacterium wereWeissella(84.62 %),Lactobacillus(8.79 %),Bacillus(3.30 %),Acetobacter(2.20 %) andLeuconostoc(1.10 %). The compositions of volatile components in Chinese steamed bread (CSB) fermented with the traditional Jiaozi were determined by solid phase microextraction (SPME) coupled with gas chromatography -mass spectrometry (GC-MS). 59 volatile compounds were detected in CBSs by Jiaozi including 17 kind of alcohols, 8 kind of hydrocarbons, 15 kind of esters, 9 kind of aldehydes, 4 kind of ketones, 5 kind of aromatics and 1 kind of other compounds, which was more than in dry yeast starters. Combining quantitative and qualitative analysis, the content and variety of alcohols is the main marker to distinguish the two CSBs. This study revealed that the traditional Jiaozi had a complex composition of bacteria, and produced rich flavor compounds in CBS fermentation. This study supplied the basic data for industrialization of traditional staple food and supplied strain source for the further study of biological function research and supplied a new idea of the development of nutrition of traditional staple food.