目的　研究小剂量阿司匹林对胃黏膜的损伤 ,了解肿瘤坏死因子 (TNF α)是否参与小剂量阿司匹林引起的胃黏膜损伤。方法　用小剂量阿司匹林灌服大鼠 ,观察大鼠胃黏膜损伤情况 ;应用免疫组化方法检测TNF α在胃黏膜细胞的表达。结果　灌胃后 3d实验组开始出现胃黏膜损伤 ,免疫组化结果示TNF α在用药后 3d开始表达 ,1 4d达高峰 ,2 1d开始下降。TNF α与损伤指数呈正相关。结论　小剂量阿司匹林可造成胃黏膜损伤 ,TNF α在小剂量阿司匹林引起的胃黏膜损伤的发病机制中具有一定的作用 Objective To study the effect of low-dose aspirin on gastric mucosal injury and to investigate whether tumor necrosis factor (TNFα) is involved in gastric mucosal lesion caused by low-dose aspirin. Methods A small dose of aspirin was administered to rats to observe the gastric mucosal injury. The expression of TNFα in gastric mucosal cells was detected by immunohistochemistry. Results Gastric mucosal injury began to occur in experimental group 3 days after gavage. The results of immunohistochemistry showed that TNFα began to be expressed on the third day after administration, peaked on the 14th day, and decreased on the 21st day. TNFα was positively correlated with injury index. Conclusion Low-dose aspirin can cause gastric mucosal injury. TNFα may play a role in the pathogenesis of gastric mucosal injury induced by low-dose aspirin