Objective：To evaluate expressions of angiopoietin2（Ang2） protein in human gastric cancer cells SGC-7901 transfected by pEPFP-N1-antisense Ang2 and to investigate whether antisense Ang2 gene could inhibit the vitro growth of human gastric carcinoma cell line. Methods：Two different plasmids including pEGFP-N1 and pEGFP-N1 SGC-7901 antisense Ang2 were separately trans－ferred into an in vitro cultured human gastric cancer cell line SGC-7901 using Lipofectamine2000 transfection technique. After trans－fection，the cells were selected by G418. Then resistant clones were chosen and expanded in DMEM culture medium，with parental SGC-7901 cells as control. RT-PCR and immunohistochemical method were done to determine whether target genes and its proteins had expressed. Cell viability was determined by MTT assay. Apoptosis was determined by flow cytometry with a double dyeing method using FITC-conjugated annexin V and PI. Results：According to results of RT-PCR and immunohistochemical methods，angiopoietin mRNA and its proteins were not expressed in transfected antisense Ang2 gene SGC-7901 cells. MTT assay showed that pEGFP-N1-anti Ang2 transfection group had much lower cell viability than other groups（F=10.39，P=0.002 4）. Meanwhile，pEGFP-N1-anti Ang2 transfection group had an increase in apoptosis rates compared with those of the other groups based on results of flow cytometry（?字2=3 188.98，P＜0.000 1）. Conclusions：pEGFP-N1-anti Ang2 successfully transfects human gastric cancer cells SGC-7901，which in－hibits Ang2 mRNA and protein expressions as well as suppresses the malignant phenotype of human gastric cells.