Isolated from a Guangdong rice vinegar factory,the RF4 Gluconacetobacter xylinus is used to produce rice vinegar by surface fermentation.The effect of intact bacterial cellulose pellicle on total acidity in fermentation,the comparison of ADH enzyme activity in the pellicle and liquor,and the influence of inoculation methods on acidity,viscosity and turbidity are researched.The results show that the morphology of bacterial cellulose pellicle is very important to total acidity produced,and the ADH enzyme activity in the bacterial cellulose pellicle is 2.26×10~-2U/g,8 times of that in the liquor.The highest acidity achieved when bacterial cellulose pellicle was inoculated with Gluconacetobacter xylinus,and was taken out during the fermentation,resulting in a high yielding of 4.86g/100mL after 12 days accompanying by low viscosity and turbidity.