Based　on　the　preparation　and　characterization　of　controlled　release　antibacterial　material-ciprofloxacin-polyurethanes　(CFPU),　the　method　of　HPLC　was　established　to　determine　the　content　of　antibacterial　agent-ciprofloxacin　(CF)　in　the　degradation　solution　of　CFPU　and　investigate　the　drug-release　mechanism　in　vitro　by　plotting　and　fitting　the　cumulative　release　curves　to　inspect　the　effects　of　different　medium　and　different　concentrations　on　drug　release.　The　results　showed　that　the　HPLC　method　is　accurate,　reliable　and　simple.　The　drug-release　of　CFPU　was　bioresponsive　and　could　be　accorded　with　first　order　kinetics.　It　was　observed　that　CF　was　released　from　CFPU　by　a　combination　of　diffusion　and　erosion　mechanism　by　modeling　in　the　Ritger-Pappas　equation　(0.45＜n＜0.89),　mainly　in　the　manner　of　diffusion　in　the　absence　of　infection　while　erosion　mechanism　in　the　presence　of　infection.　And　the　worse　the　inflammation　was,　the　more　erosion　mechanism　dominated.