Abstract: This paper presents the determination of antinuclear antibodies and its specificities as ds-DNA antibodies, Sm antibodies and n-RNP antibodies of both blood and urine in 46 cases of lupus nephritis with heavy proteinuria and 7 cases of SLE without proteinuria. In the former group, the positive rate of blood was ANA 63%>ds-DNA antibodies 50%> n_RNP antibodies 37%>Sm antibodies 22.7%.