The present disclosure provides a pharmaceutical composition for treating or alleviating an autoimmune disease and/or complication thereof and/or nephritis, including: an effective amount of an extract of a plant belonging to Rutaceae as an effective ingredient for treating or alleviating the autoimmune disease and/or complication thereof and/or nephritis, wherein the autoimmune disease is selected from a group consisting of lupus erythematosus, psoriasis, psoriatic arthritis, ankylosing spondylitis, rheumatoid arthritis, juvenile idiopathic arthritis, Crohn's disease and ulcerative colitis (UC).