ObjectiveTo study the expression levels of miR-339-3p and miR-339-5p in the gastric carcinoma cell lines(SGC-7901, BGC-823, and MKN-45) and gastric surface epithelium(GES-1);detect the relationship between miR-339-3p and miR-339-5p and the gastric carcinoma cell lines in vetrio experiment through the gain of function, and further significance is suggested. MethodsSYBR greenⅠreal time PCR was performed to access the expression of miR-339-3p and miR-339-5p in different cell lines(SGC-7901, BGC-823, MKN-45, and GES-1). The expression levels of miR-339-3p and miR-339-5p were verified by real time PCR experiment again after transfecting miR-339-3p mimics and miR-339-5p mimics. After that, the changes of MKN-45 cells apoptosis and proliferation at 72 h after transfection were detected by flow cytometry and CCK-8 method. ResultsThe expression levels of miR-339-3p and miR-339-5p in gastric carcinoma cell lines(SGC-7901, BGC-823, and MKN-45) were down regulated. Compared with the control group, the apoptosis of MKN-45 cell line was significantly higher(P < 0.05), the ability of proliferation of MKN-45 cell line decreased after transfecting miR-339-3p mimics and miR-339-5p mimics within 72 hours(P < 0.01). ConclusionThe expression levels of miR-339-3p and miR-339-5p significantly decreased in the gastric carcinoma cell lines(SGC-7901, BGC-823, and MKN-45) in contrast with gastric surface epithelium. MiR-339-3p and miR-339-5p may be involved in the apoptosis and proferation of the gastric carcinoma.