We studied thrity patients with Systemic lupus erythematosus (SLE)and ten healthy control subjects .Our work aimed at studying polymorphism of the CD152 exon-1 gene in association with SLE. Our study showed a higher prevalence of G/G genotype of CD152 exon-1 +49 in patients than in the control subjects [ 25 cases(83.3%) versus 2 controlsubjects(20% )]; p-value <0.05 indicating statistical significance and thatpatients with G/G genotype of CD152 exon-1 +49 are more susceptible todevelop SLE .