The present invention provides the method for processing or with 2 preventing autoimmune disease, 4 pyrimidinediamine compounds, and processing method, prevent or improve symptom associated with such disease. Can be processed by compound or the specific example of autoimmune diseases that prevents include rheumatoid arthritis and/or its relevant symptom, the feather fan erythematosis of system and/or its relevant symptom and multiple sclerosis and/or its relevant symptom.