For the purpose of revealing the influence of Eurotium Cristatum on content of free-state fluorine in tea , Eurotium Cristatum original strains and a mutant strain were used as pure strains during the fungus growing process of maojian tea(green tea) and raw dark green tea. Then the content of free-state fluorine in tea before and after the fungus growing process and in “Golden Flower” pellets were determined respectively. Also, the concentration of free-state fluorine in tea infusion before and after liquid fermentation with Eurotium Cristatum strain was determined. The results showed that both Eurotium Cristatum original strains and the mutant strain could increase the content of free-state fluorine in raw dark green tea by 7.94% and 10.47% respectively as compared with the tea that not inoculated the Fungi. But there was no influence on the content of free-state fluorine in maojian tea. “Golden Flower” pellets contained some free-state fluorine. Eurotium Cristatum strain could absorb a small amounts of free-state fluorine in tea infusion, but there was no dependency between absorptive amount and original concentration of free-state fluorine. Influence of Eurotium Cristatum strains on the content of free-state fluorine in tea was differed with the original level of fluorine in different tea, also, Eurotium Cristatum strains couldn’t concentrate the fluorine from environment.