Label-free quantitative proteomics for inflamed and matched normal colonic mucosa in ulcerative colitis (UC) patients was used for discovery of differential expressed proteins. Compared to normal colonic mucosa, we found that 69 upregulated proteins and 70 downregulated proteins in UC patients according to fold change ≥ 2, p ≤ 0.05. Then, we will study the potential mechanism according to differential expressed proteins.