Objective By examining the protein expression of Caspase-9 and c-IAP1 in gastric adenocarcinoma tissues, to explore their relationship with the development and progression of gastric adenocarcinoma; and the correlation between the two. Methods The protein expressions of Caspase-9 and c-IAP1 were detected in 50 cases of gastric adenocarcinoma tissues and 40 cases of normal gastric mucosa tissues,byimmunohistochemical method. Results The expression of Caspase-9 protein in gastric adenocarcinoma was significantly lower than that of normal gastric mucosa(P<0.05);The expression of Caspase-9 protein in gastric adenocarcinoma tissues were significantly correlated with histological differentiation,TNM clinical stage and lymph node metastasis(P<0.05),while there was no correlation with gender, age and depth of invasion (P>0.05).The expression of c-IAP1 protein in gastric adenocarcinoma was significantly higher than that of normal gastric mucosa (P<0.05);The expression of c-IAP1 protein in gastric adenocarcinoma tissues were significantly correlated with histological differentiation,TNM clinical stage, lymph node metastasis and depth of invasion (P<0.05),while there was no correlation with gender and age (P>0.05). There was a negative correlation between the expression of Caspase-9 and c-IAP1 in gastric adenocarcinoma tissues (r _s=-0.578, P<0.05). Conclusion The expression of Caspase-9 and c-IAP1 in gastric adenocarcinoma tissues was negatively correlated, and their abnormal expression participated in the development and progression of gastric adenocarcinoma.