1. On the studies of the relatives of patients with SLE, a family was found in which two sisters were affected with SLE and other two showed positive tests for ANF. In another family, two were positive for ANF, other two families had one positive to ANF. In summery the number being positive for ANF was six (four females and two males). 2. It was emphasized on the basis of the results of various clinical and experimental conditions, that not only genetic factors but also functional unbalance among the genital glands, adrenortex and antibody-producing tissues participated in the onset of autoimmune diseases, especially SLE. 3. Serum γ and α(2) globulin levels were high in majority of SLE. In the course of treatment, there were two cases in which hypergammaglobulinemia became normal and beta-globulin was increased. This hyper-beta-globulinemia may indicate the increased complemental compoments in the serum. 4. All of clinically diagnosed 11 cases of SLE showed a positive LE cell test. The two-hour clotting method was the most sensitive and the cover-glass method followed. The LE factor had been shown to be 7S and 19S globulins by the direct fluorescent antibody technique. 5. ANF was positive in all cases of SLE, even those in remission. The most cases were showed to be heterogenous in all three immunoglobulin classes. IgG ANF was the highest in the titer and persisted for a long period though its titer gradually became low. On the contrary, IgM or IgA ANF (especially the latter) gradually diminished during remission. There were a poor correlation between fluorescent patterns and the types of nuclear antigens.