Abstract: The acetate content of 70¹30h fermented vinasse which was the fresh vinasse as raw material by the acid-base titration was periodically measured. The effect of the ingredients and temperature ratio on the acetic acid production was discussed, and the finished nature of vinasse vinegar was determined after fermentation. The result showed that in the fermentation of 70¹30h, the total yield of the fermented vinasse vinegar trend was first increased and then decreased, peak in acetic acid content 100h. So the suitable fermentation time should be 100h. The main factors to affect the flavor of the vinasse vinegar were fermentation temperature, the initial alcohol concentration. The technological conditions for fermenting vinegar via vinasse was that:the proportion of ingredients of 5∶ 3∶ 1, acetic acid bacteria inoculum amount of 0. 7%, the initial alcohol concentration of 6. 0%, the temperature of fermentation of 30℃, fermentation time of 100h. The acetic acid content of the finished product vinasse vinegar was 50. 0g/L, the amino nitrogen content was 30. 0g/L. The results of this study laid the theoretical foundation for further use of waste vinasse to product the slightly mellow and soft sour vinegar.