Abstract: Objective：To evaluate the inhibitory activity of farnesol to the Candida albicans biofilms in vitro. Methods：Candida albicans biofilms were formed on flat-bottom 96-well microtiter plates and two study groups (12 h and 24 h Group) were noted, then respectively incubated in the RPMI 1640 with different concentration of farnesol (100-900 μmol/L) for 24 h. The XTT reduction assay was employed to evaluate the inhibitory effect of farnesol to the biofilms. Biofilm morphology was observed by inverted microscope. Results：Farnesol （100 -900 μmol/L） has inhibitory effect on Candida albicans biofilms. With the increase of concentration of farnesol, the inhibition rate tends to increas.The sessile minimal inhibitory concentration 50%（SMIC50）of 12 h biofilm is 200 μmol/L；the SMIC50 of 24 h biofilm is 200 μmol/L. Conclusions：The inhibitory effect of Farnesol on C. albicans biofilms was obvious.The inhibitory potency of farnesol was associated with its concentration and the phase of biofilms,and the farnesol of higher concentration are more effective than that of lower concentration.