Objective To explore the clinical significance of serum neutrophil gelatinase-associated lipocalin (NGAL) in patients with ulcerative colitis (UC). Methods The serum NGAL in 89 patients with UC and healthy controls were measured by using latex-enhanced immunoturbidimetric assay. The correlation between serum NGAL and blood WBC counts, PLT counts, CRP, Hgb, HCT, ESR, age, disease activity index (DAI) were analyzed. Results The serum NGAL levels in UC patients were markedly higher than that of the controls (P<0.0001). The serum NGAL levels in mild UC group were obviously lower than that in moderate-severe UC group (78.2 vs 67.2ng/mL, P=0.006). There was no correlation between serum NGAL in UC patients and WBC counts, PLT counts, CRP, Hgb, HCT and ESR, age ( P>0.05). The serum NGAL levels in UC patients was mildly positively correlated with disease activity index （r=0.525, P<0.0001）. Conclusion The serum NGAL level in patients with UC is elevated and related with DAI, but its role in patients with UC needs to be further studied.