Abstract: Apple vinegar was brewed with apple wine and strain of Gluconacetobacter xylinus RF4, the influences of the bacterial cellulose pellicle and two inoculation methods on fermentation were discussed in the paper, the differences of ADH enzyme activity between cellulose pellicle and fermented liquid, analyzed the relationship of acid production rate, oxygen consumption and the ADH enzyme activity within 32 hours after the formed pellicle was separated from the fermentation system were compared. The results showed that ADH enzyme activity in cellulose pellicle was 56 times of that in fermented liquid. After inoculating cellulose pellicle and liquid containing the bacteria respectively, both of them could reach the highest acidity 4.32g/100 mL, but the former would reach the peak faster. The bacterial cellulose pellicle was the main place of acetic acid production and its formation and intactness played a key role in the fermentation system.