Abstract: In order to reveal changes of main physical and chemical indexes during main fermentation process in mulberry wine,pH,total acid,volatile acidity,alcohol content,sugar,dry extract,organic acid and sensory were analyzed under the fermentation conditions of sugar 150 g/L,citric acid addition 1 g/L,temperature 26℃ and yeast inoculation amount 2 g/L. The results showed that during main fermentation process,the pH decreased at the beginning of the fermentation,and then increased. The change of total acid was opposite to pH value. Volatile acidity,alcohol content and dry extract increased gradually. The content of residual sugar decreased continuously. After 6 days of fermentation,indexes tended to be stable. After the end of fermentation,physical and chemical indicator were the pH4.22,the total acid 4.31 g/L,the volatile acidity 0.72 g/L,the alcohol content 7.22%vol,the dry extract 20.15 g/L,the residual sugar 1.55 g/L respectively. Among the organic acid in mulberry wine,the content of tartaric acid,lactic acid and citric acid were high relatively and were 2.184,2.303 and 1.115 g/L respectively. The sensory analysis showed that mulberry wine was perfect after 6 days of fermentation and the main fermentation finished.