Objective To investigate the effect of the replication-deficient adenovirus carrying miR-138(Ad-miR138) on the pro-liferation of human gastric cancer cell line BGC-823 and the possible mechanism .Methods The human gastric cancer cell line BGC-823 was infected with Ad-miR138 .Then the expression level of miR-138 was measured by RT-PCR .The growth curve of BGC-823 was measured using CCK-8 method .The ability of cell invasion was measured using Transwell chambers .Results After infected with Ad-miR138 ,the expression of miR-138 in BGC-823 cells was up -regulated significantly (1 .07 ± 0 .07 vs .4 .89 ± 0 .45 ,P<0 .05) .Absorbance of the 6th day decreased significantly (0 .52 ± 0 .06 vs .0 .77 ± 0 .06 ,P<0 .05) ,and the invasion ability was de-creased obviously (32 .00 ± 11 .00 vs .56 .00 ± 12 .00 ,P<0 .05) .Conclusion miR-138 can effectively suppress the proliferation and invasion of human gastric cancer cell line BGC-823 in vitro .