The method of Plackett-Burman design and response surface analysis based on the results of one-factor experiments was used to optimize the Kvass fermentation conditions. First,three factors that have an important impact on the Kvass quality were selected from material ratio,proportion of yeast and lactic acid bacteria,inoculum size,fermentation time and fermentation temperature with the Plackett-Burman design. The results showed that material ratio, proportion of yeast and lactic acid bacteria,inoculum concentration were the factors that had important impact on the Kvass quality. Then,the steepest climbing test and Box-behnken design were used to further optimize the conditions. The finial determined conditions were as follows: maize content of 24. 5%,strain ratio of Lactobacillus helveticus and Anqi yeast 2. 5∶ 1,inoculum concentration 5. 0%,fermentation time 22h,fermentation temperature at 37℃. The titritable acidity and concentration of alcohol of the kvass sample under optimized fermentation conditions were 28. 5°T and 1. 6%,respectively.