Background: In the past, researchers have looked for a variety of blood and urinary indicators for lupus nephritis (LN) in the hopes of identifying one that accurately reflects disease activity. Urinary alpha one antitrypsin is a new potential biomarker in detection of lupus nephritis which was discussed in this research. Capillaroscopic alterations have been shown to correlate with disease activity, including LN, suggesting that they may be helpful in assessing disease severity. Methods: Fifty individuals with SLE (as determined by the Systemic Lupus Erythematosus Disease Activity Index; SLEDAI) who also had at least six nailfolds suitable for microscopic evaluation participated in the research. Complete blood count (CBC), serum creatinine, and other diagnostic tests: blood urea and eGFR, Erythrocyte Sedimentation Rate (ESR), diagnostic marker for lupus (Anti -Nuclear Anti body (ANA), Anti-ds-DNA and Serum complement level (C3&C4), 24-hour urinary protein, complete urine analysis and urinary alpha one antichymotrypsin using ELISA technique in addition to nailfold capillaroscopic changes test (NFC). Results: Comparison between the normal and minor change group and between normal and major change group according to Urinary ALPH 1ACT, SLE activity, cutaneous manifestation showed high statistical significance p<0.001. There was Strong positive significant correlation between cases with SLE activity and had capillarscopic changes and high Urinary ALPH 1ACT. There was Strong positive significant correlation between urinary ALPH 1ACT, serum creatinine and 24HR urinary proteins. Conclusions: Urinary ALPH 1ACT is new potential biomarker of lupus nephritis, it was elevated in active SLE cases particularly active lupus nephritis and also with cases with capillaroscopic changes.