Abstract: Systemic Lupus Erythemattosus (SLE) is a prototypical auto immuno disease characterized by the production of the auto antibodies, the aim of present study is to determine the distribution of the alleles of Mannose-binding Lectin (MBL) gene codon 52, 54 and 57 and promoter variants H/L, X/Y, P and Q in SLE patients while compares then with normal control and seek correlation between these variants and disease that cause renal dysfunction. Twelve SLE patients with renal failure samples were compared with thirty normal controls from Azarbaijan population of Iran. MBL genotypes were investigated by polymerase chain reaction and restriction fragment length polymorphism. Allelic and genotypic frequency of the polymorphism at position- 550,+4 and at codon 52, 54 and 57 did not show statistical differences between SLE patients and controls but frequency of Lx haplotype of promoter was observed in patients with SLE and Renal failure (p = 0.0518). Present findings showed that presence of LX haplotype that cause low concentration of MBL in serum can de a risk factor for severity of systemic Lupus Erythematosus and susceptibility to renal dysfunctions.