Systemic adiministrations of antibiotics are most commonly used modes of treatment in management of otitis media, but adequate tissue concentration of antilbiotics cannot be always achieved. In contrast, topical use of antibiotics can include high level of tissue concentration, but it cannot be maintained for a long time. In order to improve the therapeutic effect of antibiotics in the middle ear, a fibrin-based drug delivery system was designed and in vitro efficacy was evaluated. Four kinds of fibrin clot were made using Ampicillin, Gentamicin and Ofloxacin respectively and biologic assay was performed using Bacillus Subtilis. All three antibiotics tested were found to be released more slowly from the fibrin-gelatin-antibiotic mixture than fibin-antibiotic mixture. Especially Gentamicin group demonstrate antibiotic activity up to 120hours against Bacillus Subtilis. This results suggest the possibility of clinical application of this new device.