Background:The autoimmune disease systemic lupus erythematosus (SLE) causes inflammation. Activity evaluation could be conducted using a number of different methods. Biomarkers like β2 is a biomarker, which is found on all nucleated somatic cells and its use as a prognostic is under investigation. Objective: The study aimed to assess the association between serum levels of β2 microglobulin (B2M) and disease activity. Patients and Methods: The study included fifty lupus patients and fifty healthy people served as controls. The levels of C-reactive protein (CRP), complement 3, and complement 4, as well as the erythrocyte sedimentation rate (ESR), anti-nuclear antibody (ANA), and anti-double-stranded DNA antibody (dsDNA), were measured. The serum Beta 2-microglobulin (B2M) was measured using an enzyme-linked immunosorbent assay. Results: The serum B2-microglobulin levels were significantly higher in SLE patients (mean values 27.42± 5.5) compared with the controls (6.80± 1.61) (P value =0.001). In contrast to inactive individuals, active patients had a greater mean serum B2-microglobulin concentration. Conclusion: A good correlation between B2M and SLE disease activity may explain the role of this marker in the inflammatory process.