The infection and tissue damage around the biomaterials are mainly caused by the bacterial adherence to the surface of the material. A new kind of antibacterial ciprofloxacin-polyurethane ( CFPU) was synthesized in order to prevent the infection. The degradation of CFPU in the phosphate-buffer saline ( PBS) ( pH =7.4

37 ℃) was studied. The antibacterial ability and the cytotoxicity of the degradation so lutions were assayed. The results showed that ciprofloxacin( CF) was kept effectively in CFPU while the drug loss was below 2% under the mimetic humoral condition. In the presence of cholesteral esterase( CE)

CF release was obviously larger than in the PBS only. Hence

the increase of the concentration of CE accelerated the release of CF

which indicated the control release ability of the material. The enzymatic degradation showed an ability to kill bacteria and the minimum inhibitory concentration ( MIC ) was measured as 0.376μg/mL. The degradation solutions were hypotoxicity according to the MTT assay.