a monoclonal antibody against the duck tembusu virus and a hybridoma cell line secreting the monoclonal antibody , a reagent kit and method for detecting a duck tembusu virus antibody , and application of the monoclonal antibody in preparing products for diagnosing the duck tembusu virus disease . the monoclonal antibody may bind specifically to e protein of duck tembusu virus and has an activity of neutralizing duck tembusu virus .