Phage Display Technology has emerged as a powerful and effective tool for the generation of Recombinant antibodies, both as phage displaying form as well as soluble form. These antibodies are infact very much comparable and found to be more effective than monoclonal antibodies. This book comprises of the Production of Phage Display antibodies against NP of Avian Influenza and its use of the recombinant antibodies in Immunodiagnosis of Avian Influenza.