Objective To explore the expression of tumor necrosis factor (TNF) mRNA, TNF and TNFR in the gallbladder mucosa which developed from hyperplasia, dysplasia to carcinoma, and to further discuss the relationship between TNF and pathogenesis of gallbladder carcinoma. Methods In situ hybridization and immunohistochemistry were used to determine TNF mRNA, TNF protein and TNFR protein expression in hyperplasia, dysplasia and carcinoma of gallbladder. Results ①No one of 20 cases of gallbladder hyperplasia was found to express TNF mRNA, while 4 of 20 (20%) cases of dysplasia and 18 of 20 (90%) cases of carcinoma were found to express TNF mRNA (P＜0.05). ②For the expression of TNF mRNA in mononuclear cells (MNC), positive staining was found in 15% of gallbladder hyperplasia, 85% of dysplasia and 90% of carcinoma, respectively (P＜0.05). The cell numbers of positive staining MNC were 4.85±1.50, 6.00±2.71 and 9.33±3.07, respectively (P＜0.05). ③In gallbladder carcinoma, the cell number of carcinoma and MNC with positive TNF mRNA expression was correlated with clinical stage (P＜0.05). The higher the clinical stage, the more the positive staining cell numbers. The positive staining cell numbers of carcinoma in stage Ⅰ-Ⅲ and Ⅳ-Ⅴ were 9.13±4.39 and 14.80±4.02, respectively (P＜0.01), and the positive staining cell numbers of MNC were 7.13±2.53 and 11.10±2.23, respectively (P＜0.05). ④The cell numbers of carcinoma and MNC with TNF mRNA expression increased with tumor size. In tumors with diameter over 2 cm and less than 2 cm, the positive staining cell numbers of carcinoma were 14.00±4.20 and 8.83±4.96, respectively (P＜0.05), and that of MNC were 10.50±2.54 and 7.00±2.83, respectively (P＜0.05). ⑤The region of TNF protein expression was similar to that of TNF mRNA, but TNF protein expression was more frequent and wider than that of TNF mRNA. ⑥The tumor necrosis factor receptor was expressed in tumoral vascular endothelial cells and MNC in all cases of carcinoma, but was negatively stained in mucosa epithelial cells and tumor cells of all cases. ⑦There was positive linear correlation in TNF mRNA between tumor cell and MNC (r=0.687, P＜0.01), same as that in TNF protein expression (r=0.742, P＜0.01); and there was positive linear correlation in tumor cell between TNF mRNA and TNF protein expression (r=0.847, P＜0.01), same as that in MNC (r=0.643, P＜0.01). Conclusion The TNF mRNA and TNF protein expression are increasing during the development of gallbladder mucosa epithelial from hyperplasia, dysplasia to carcinoma, and increasing with tumor stage. It suggests that TNF may contribute to carcinogenesis of gallbladder carcinoma induced by gallstone, and related to the progression of gallbladder carcinoma.