Abstract: The present invention relates to an immunocytokine in which a human interferon-beta variant is conjugated to an antibody or a fragment thereof, and a method for preparing the same. The human interferon-beta variant has superior activity or functions compared with natural interferon-beta, and the productivity of the immunocytokine according to the present invention is excellent. In addition, the immunocytokine according to the present invention can be favorably used as a target therapeutic agent for multiple sclerosis or cancer since the immunocytokine express both of functions of the interferon-beta and characteristics of the antibody binding to a specific antigen.