Aim:to investigate the levels of urinary monocyte chemoattractant protein-1(uMCP-1)to monitor the disease activity and lupus nephritis(LN)flare.Patients and Methods::This study included 102 urine samples from 17 LN patients,that were collected every months for 6 months,then examined for uMCP-1,renal domain SLEDAI scores and degree of flare(mild,moderate and severe)based on OHIO SLE study(OSS).The urine levels of MCP-1 was measured by ELISA technique.Results:The levels of uMCP-1 were higher in the active group than the inactive LN group(p=0.004).There was significant positive correlation between uMCP-1 levels with renal domain SLEDAI scores(p< 0.001,r = 0.532).The levels of uMCP-1 were higher in the LN flare group than the non flare group(p= 0.001).There was not significant differance in the levels of uMCP-1 between mild,moderate and severe LN flare groups(p > 0.05).Elevated levels of uMCP-1(cut off point was 29.38 ng/ml)had sensitivity 65.6%,and specificity 64.2%to determine LN flare.Conclusion::The levels of urinary MCP-1 was a better biomarker to monitor LN disease activity than degree of LN flare.