The present invention relates to a stem cell having an immunosuppressive ability in which the expression or activity of a suppressor of cytokine signaling (SOCS) is inhibited, and a pharmaceutical composition for inhibiting immunity, which includes the stem cell. In addition, the present invention relates to a composition for inducing the immunosuppressive activity of a stem cell, including a suppressor of cytokine signaling (SOCS) expression or activity inhibitor. The inhibition of suppressor of cytokine signaling (SOCS) expression or activity, according to the present invention, may enhance the immunosuppressive ability of a stem cell, and the stem cell with enhanced immunosuppressive ability may be used as an effective cell therapeutic agent in an autoimmune disease, rejection upon organ transplantation, or an allergic disease.
