Abstract: Objective To investigate the role of trefoil factor 1 (TFF1) expression in gastric mucosa healing and carcinoma suppression. Methods TEF1 expressions in normal and pathological gastric mucosa tissues were detected by immunohistochemical analysis, and the average optical density (OD) was estimated by Motic Images Advanced 3.0 software. Results Increased TFF1 expression was detected in gastritis, gastric ulcer and duodenal ulcer tissues as compared with that in normal gastric mucosa. TFF1 expression was increased in multiple and compound ulcer in comparison with simple ulcer, but there was no significant difference between gastric ulcer and duodenal ulcer, or between gastritis and simple ulcer tissues. Increased TFF1 was also detected in the mucosa adjacent to the gastric adenocarcinoma, and adenocarcinoma with poorer differentiation had lower TFF1 expression. Conclusions TFF1 expression is increased in gastritis, gastric ulcer and duodenal ulcer, and multiple and compound ulcer has higher TFF1 expression than simple ulcer, suggesting the protective role of TFF1 in gastric mucosa and epithelial restitution. TFF1 may directly contribute to the differentiation of adenocarcinoma, and the poorer the differentiation, the lower the expression of TFF1.