Abstract: Objective To observe the difference of urinary levels of neutrophil gelatinase-associated apolipoprotein (NGAL) and matrix metalloproteinase-9 (MMP-9) in patients with ulcerative colitis and healthy volunteers. To explore the clinical significance of detection of NGAL and MMP-9 in urine of patients with ulcerative colitis. Methods The levels of NGAL and MMP-9 in urine of patients with ulcerative colitis were detected by double antibody sandwich enzyme linked immunosorbent assay (ELISA). The changes of urinary NGAL and MMP-9 levels in active and remission patients were observed and compared with those in healthy controls. Results The levels of urinary NGAL in the patients of active ulcerative colitis were significantly higher than those in healthy controls [(37.71±12.69)ng/mL vs. (19.27±5.34)ng/mL, P<0.01]. The difference was statistically significant. The levels of urinary MMP-9 in the patients of active ulcerative colitis were significantly higher than those in healthy controls [(5.14±1.25)ng/mL vs. (1.06±0.32)ng/mL, P<0.01]. The difference was statistically significant. After treatments, the levels of urinary NGAL in patients with ulcerative colitis was significantly lower than those in active phase [(36.34±11.83)ng/mL vs. (25.13±5.76)ng/mL, P<0.05]. The difference was statistically significant.After treatments, the levels of urinary MMP-9 in patients with ulcerative colitis was significantly lower than those in active phase [(5.38±1.62)ng/mL vs. (3.09±0.67)ng/mL, P<0.05]. The difference was statistically significant. Conclusion The levels of urinary NGAL and MMP-9 in patients with active ulcerative colitis are significantly higher than those of control group. After treatments, the levels of urinary NGAL and MMP-9 in patients with ulcerative colitis are significantly lower than those in active phase. The detection of urinary NGAL and MMP-9 is convenient, non-invasive and no pain to the patient. It can be used as one of the monitoring methods of the ulcerative colitis.