ANXA2, a member of the annexin family, is overexpressed and plays important roles in tumor development.However, the significance of ANXA2 expression in gastric carcinoma has not been clarified.To elucidate its rolesin growth of gastric cancer, ANXA2 expression in SGC-7901 cells was inhibited with a designated siRNA, thencell proliferation, cell cycling, apoptosis and motility were determined by MTT assay, flow cytometry, Hoechst33342 staining and wound healing assay, respectively. To further assess the behavior of ANXA2 deleted SGC-7901 cells, changes of microstructures were observed under fluorescence microscopy, laser scanning confocalmicroscopy and electron microscopy. We found that inhibition of ANXA2 expression caused cell proliferationto decrease significantly with G1 arrest, motility to be reduced with changes in pseudopodia/filopodia structureand F-actin and β-tubulin expression, and apoptosis to be enhanced albeit without significance. At the same time,ANXA2 deletion resulted in fewer pseudopodia/filopodia, non-stained areas were increased, contact inhibitionamong cells reappeared, and expression of F-actin and β-tubulin was decreased, with induction of polymerizeddisassembled forms. Taken together, these data suggest that ANXA2 overexpression is important to maintainthe malignancy of cancer cells, and this member of the annexin family has potential to be considered as a targetfor the gene therapy of gastric carcinoma.