MicroRNAs (miRNAs) play crucial roles in the development and progression of human cancers, including Gastric cancer (GC). In this study, we investigated the correlation of miR-122-5p expression with cell proliferation, and apoptosis in a GC cell line. GC cells SCG 7901 were transfected with control, miR-122-5p or miR-122-5p inhibitor and MTT assay, western blot, and BrdU staining were respectively used to investigate the effect of miR-122-5p on GC cell cycle. The overexpression of miR-122-5p could reduce cell proliferation in SCG7901 cells, and BrdU staining finally verified miR-122-5p induced cell growth arrest by upregulation p27 expression in SCG7901cells. On the other hand, cells apoptosis research showed that miR-122-5p induced apoptosis by targeting MYC in SCG7901 cells. Finally, in this study, miR-122-5p was confirmed inhibiting tumor GC cells proliferation and inducing cells apoptosis by targeting MYC. All these findings suggest that miR-122-5p may be involved in progression of GC and could be a new therapeutic target for this disease.