The infection of S. epidermidis, an opportunistic human pathogen, depends on biofilm formation, and biofilm formation is closely related to environment. Researches in the thesis focused on two strains of S. epidermidis with different capability of biofilm formation. To find the mechanism of response to environment on biofilm formation, biofilm formation and expression of ica, icaR, AtlE in theses S. epidermidis cultivated in different grow environment and in media with glucose for different time were assayed. Glucose can induce the biofilm formation by inducing ica gene, but the inducing do not need continued ica expression, and other genes also contribute to the regulation; anti-ODN specially binding icaADBC can withstand biofilm inducing from glucose. These results suggest that biofilm formation closely related to growth environment, which is a complex regulation mechanism. Biofilm formation is closely related to bacteria energy metabolism and cell wall synthesis. Some crucial factors in the complex and integrated regulation system have not been known yet.