Systemic Lupus Erthymatosous (SLE) is achronic inflammatory multi system auto immue disease characterized by pathogenic auto anti bodies production against nuclear structures (Bolouri et al.,2022), SLE affecting mainly woemn of childbearing age and is chracterized by unpredictable flares and remissions , disease variety varied from mild episode disorder to arpidly progressive life -threatening illness.. LN is diagnosed by either the presence of proteinuria \>0.5g/day. active urinary sediment , or an unexplained rise in serum creatinine there fore , identifying new invasive biomarkers of LN severity and outcome is mandatory, Renal Arterial resistive index ( RRI) is anon invasive biomarker that has been studied as apotential indicator of disease activity in LN patients.