Objective To investigate the expression and significance of Bax,cyclooxygenase- 2( COX2),and inhibitor of differentiation 1( ID1) in gallbladder adenocarcinoma tissues. Methods A total of 70 patients confirmed with gallbladder adenocarcinoma by pathological examination in the Department of Pathology,The First Hospital of Lanzhou University,from 2000 to 2013 were collected. Besides,20 cases of high- grade intraepithelial neoplasia,30 cases of low- grade intraepithelial neoplasia,and 20 cases of cholecystitis were selected as controls. The protein expression of Bax,COX2,and ID1 in the four groups was determined using the immunohistochemical SP method. Meanwhile,chi- square test was conducted on the data using fourfold table exact test,the correlations between Bax,COX2,and ID1 were determined by Spearman correlation analysis,and survival data were subjected to Kapan- Meier survival analysis. Results The high- grade intraepithelial neoplasia group,low- grade intraepithelial neoplasia group,and cholecystitis group showed significantly different expression of Bax compared with the gallbladder adenocarcinoma group( all P < 0. 05); the low- grade intraepithelial neoplasia group and cholecystitis group showed significantly different expression of COX2 and ID1 compared with the gallbladder adenocarcinoma group( all P < 0. 05); the high- grade intraepithelial neoplasia group showed significantly different expression of COX2 and ID1 compared with low- grade intraepithelial neoplasia group and cholecystitis group( all P < 0. 05). Survival analysis showed that patients with positive Bax had a significantly higher survival rate than those with positive COX2 and ID1( both P < 0. 05). COX2 was positively correlated with ID1( r = 0. 329,P < 0. 05).Conclusion Bax,COX2,and ID1 may play a role in the development of gallbladder adenocarcinoma,and joint detection of Bax,COX2,and ID1 is of great significance for the prognosis of gallbladder adenocarcinoma.