Abstract: The effect of citric acid, water content and temperature on inversion of white sugar was studied in this research.Different composition of invert syrup was used in moon-cake to research the water activity, oil and water content along with storing period.The last test was analyzed by TPA for hardness, cohesiveness and chewiness.Results showed that increasing citric acid content, raised rate of sucrose inversion, and the rate was reaching 96 percent when citric content was 0.20% on the basis of sucrose.Slow inversion rate was occurred when increasing water content.48.6% sucrose was inverted when temperature was 110 centigrade, lower than 90℃ and 100℃.High inversion of sucrose, lower sucrose content was favorable in speeding up the water transferring from interior part to exterior, oil migrating was effective when citric acid addition was 0.20%.The results showed that, water content, oil content were positive analyzed with fructose and glucose, and negative with sucrose, and water activity was negative with fructose and glucose, positive analyzed with sucrose.Hardness of moon cake skin was negative with fructose and glucose, positive correlation occurred with cohesiveness and chewiness. High rate of sucrose inversion was favorable for moon-cake, because of improving the water and oil transferring.