Objective To investigate the inhibitory effect of cyclooxygenase-2 (COX-2) inhibitor celecoxib alone and in combination with somatostatin (SST) analog octreotide on human gastric cancer. Methods Fifty one gastric cancer patients were randomly divided into 3 groups. The patients in control group(n=15)took no medicine before gastric cancer resection. Celecoxib group(n=18)patients took celecoxib orally 0.2 g/d for 7 days before surgery. Combination group(n=18) patients took celecoxib orally 0.2 g/d and were injected octreotide 100 ?g/d subcutaneously for 7 days before surgery. The resected specimens were examined histologically, including status of tumor necrosis, inflammatory cells infiltration and fibrous tissue proliferation. The microvessel density (MVD) and the expression of COX-2 in gastric cancer were evaluated by immunohistochemical methods. The apoptosis of tumor cells was measured by terminal deoxynucleotidyl transferse-mediated-dUTP nick end labeling. The expression of somatostatin receptor (SSTR) -1,SSTR-2 and SSTR-3 mRNA in gastric cancer tissue obtained by biopsy in all patients were detected by using real time fluorescence quantitative RT-PCR. Results Compared with control group, gastric cancer tissue necrosis increased significantly(P